Multi-radio access technology scheduling of sidelink interface

ABSTRACT

Methods, systems, and devices for wireless communication are described. A user equipment (UE) may receive a message indicating that a base station supports allocating resources for sidelink communications using a first radio access technology (RAT) and a second RAT that is different from the first RAT. The UE may transmit a sidelink information message to the base station using the first RAT that indicates that sidelink communications are to be performed using either the second RAT or both the first RAT and the second RAT. The UE may receive a configuration message from the base station that comprises an identifier for the sidelink communications and an indication of available sidelink resources. The UE may transmit, based at least in part on the configuration message, a request for resources within the available sidelink resources, the request indicating the identifier and a buffer status report (BSR).

CROSS REFERENCES

The present Application for Patent is a Continuation of U.S. patentapplication Ser. No. 16/276,301 by WU et al., entitled “MULTI-RADIOACCESS TECHNOLOGY SCHEDULING OF SIDELINK INTERFACE” filed Feb. 14, 2019,which claims the benefit of U.S. Provisional Patent Application No.62/637,239 by WU et al., entitled “MULTI-RADIO ACCESS TECHNOLOGYSCHEDULING OF SIDELINK INTERFACE,” filed Mar. 1, 2018, assigned to theassignee hereof, and expressly incorporated herein.

BACKGROUND

The following relates generally to wireless communications, and morespecifically to multi-radio access technology (RAT) scheduling ofsidelink interface.

Wireless communications systems are widely deployed to provide varioustypes of communication content such as voice, video, packet data,messaging, broadcast, and so on. These systems may be capable ofsupporting communication with multiple users by sharing the availablesystem resources (e.g., time, frequency, and power). Examples of suchmultiple-access systems include fourth generation (4G) systems such asLong Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, orLTE-A Pro systems, and fifth generation (5G) systems which may bereferred to as New Radio (NR) systems. These systems may employtechnologies such as code division multiple access (CDMA), time divisionmultiple access (TDMA), frequency division multiple access (FDMA),orthogonal frequency division multiple access (OFDMA), or discreteFourier transform-spread-OFDM (DFT-S-OFDM). A wireless multiple-accesscommunications system may include a number of base stations or networkaccess nodes, each simultaneously supporting communication for multiplecommunication devices, which may be otherwise known as user equipment(UE).

Wireless communication systems may include or support networks used fordirect communications between wireless devices, e.g., directcommunications between UEs. Examples of direct communications include,but are not limited to, device-to-device (D2D) communications,vehicle-based communications, which may also be referred to asvehicle-to-everything (V2X) networks, vehicle-to-vehicle (V2V) networks,cellular V2X (C-V2X) networks, and the like. The direct communicationsare generally referred to as sidelink communications and may utilize aPC5 interface. Typically, each RAT, such as an LTE RAT, a NR RAT, amillimeter wave (mmW) RAT, and the like, has its own associated set ofprotocols and/or configurations that supports the PC5 interface.

Some wireless communication systems may be configured to supportnetwork-assisted sidelink communications (e.g., mode 3 support where thebase station allocates the resources for the sidelink communications)and/or autonomous sidelink communications (e.g., mode 4 support wherethe UEs pick the sidelink resources from a resource pool of availablesidelink resources). However, some deployment scenarios may not includea base station for every available RAT being deployed in every location.This may create problems for a UE that supports sidelink communicationsusing multiple RATs, such as when the home base station does not supportallocating sidelink resources for more than one RAT.

SUMMARY

The described techniques relate to improved methods, systems, devices,and apparatuses that support multi-radio access technology (RAT)scheduling of sidelink interfaces. Generally, the described techniquesprovide an efficient mechanism that supports evolving PC5 interfacesbetween different RATs (e.g., a first RAT such as a Long Term Evolution(LTE) RAT and a second RAT such as a new radio (NR) RAT). In someaspects, this may include a base station that transmits a signal to oneor more user equipments (UEs) within its coverage area. The signal mayindicate support at the base station for the allocation of sidelinkresources on multiple RATs. For example, the base station may include aflag or a field of a system information block (SIB) message thatprovides the indication of the dual-RAT support. A UE may determine thatit has to perform sidelink communications using one or more RATs (e.g.,using the second RAT or the second RAT and the first RAT). The UE maytransmit an indication to the base station that indicates the UE intendsto perform the sidelink communications. The indication may be in, forexample, a sidelink information message. In some aspects, the UE maycommunicate the sidelink information message to the base station usingthe first RAT. The base station may receive the indication and respondby transmitting a configuration message that includes an identifier forthe sidelink communications, providing some indication of resources thatmight be available for sidelink communications, and the like.

Accordingly, the UE may respond by transmitting a resource request tothe base station. The resource request may include one or more bufferstatus reports (BSRs). The BSRs may be selected or otherwise configuredbased at least in part on whether the UE wants to perform sidelinkcommunications using just the second RAT or using both of the first andsecond RATs. For example, the UE may include a legacy BSR requestingresources for LTE RAT sidelink communications and/or an updated BSRrequesting resources for LTE RAT and NR sidelink communications. Asanother example, the UE may include a first BSR for the second RAT thatis associated with a first transmission type and a second BSR for thesecond RAT that is associated with a second transmission type.Accordingly, the base station may receive the resource request andrespond by providing one or more scheduling grants of sidelink resourcesto the UE. Thus, the base station may allocate sidelink resources thatsupport sidelink communications using more than one RAT.

A method of wireless communication at a UE is described. The method mayinclude receiving a message indicating that a base station supportsallocating resources for sidelink communications using a first RAT and asecond RAT that is different from the first RAT. The method may alsoinclude transmitting a sidelink information message to the base stationusing the first RAT that indicates that sidelink communications are tobe performed using either the second RAT or both the first RAT and thesecond RAT. The method may further include receiving a configurationmessage from the base station that comprises an identifier for thesidelink communications and an indication of available sidelinkresources. The method may also include transmitting, based at least inpart on the configuration message, a request for resources within theavailable sidelink resources, the request indicating the identifier anda BSR configured based at least in part on whether the request forresources is associated with the second RAT or both the first RAT andthe second RAT.

An apparatus for wireless communication at a UE is described. Theapparatus may include a processor, memory in electronic communicationwith the processor, and instructions stored in the memory. Theinstructions may be executable by the processor to cause the apparatusto receive a message indicating that a base station supports allocatingresources for sidelink communications using a first RAT and a second RATthat is different from the first RAT and transmit a sidelink informationmessage to the base station using the first RAT that indicates thatsidelink communications are to be performed using either the second RATor both the first RAT and the second RAT. The instructions may also beexecutable by the processor to receive a configuration message from thebase station that comprises an identifier for the sidelinkcommunications and an indication of available sidelink resources andtransmit, based at least in part on the configuration message, a requestfor resources within the available sidelink resources, the requestindicating the identifier and a BSR configured based at least in part onwhether the request for resources is associated with the second RAT orboth the first RAT and the second RAT.

Another apparatus for wireless communication at a UE is described. Theapparatus may include means for receiving a message indicating that abase station supports allocating resources for sidelink communicationsusing a first RAT and a second RAT that is different from the first RATand means for transmitting a sidelink information message to the basestation using the first RAT that indicates that sidelink communicationsare to be performed using either the second RAT or both the first RATand the second RAT. The apparatus may also include means for receiving aconfiguration message from the base station that comprises an identifierfor the sidelink communications and an indication of available sidelinkresources and means for transmitting, based at least in part on theconfiguration message, a request for resources within the availablesidelink resources, the request indicating the identifier and a BSRconfigured based at least in part on whether the request for resourcesis associated with the second RAT or both the first RAT and the secondRAT.

A non-transitory computer-readable medium storing code for wirelesscommunication at a UE is described. The code may include instructionsexecutable by a processor to receive a message indicating that a basestation supports allocating resources for sidelink communications usinga first RAT and a second RAT that is different from the first RAT andtransmit a sidelink information message to the base station using thefirst RAT that indicates that sidelink communications are to beperformed using either the second RAT or both the first RAT and thesecond RAT. The code may also include instructions executable by theprocessor to receive a configuration message from the base station thatcomprises an identifier for the sidelink communications and anindication of available sidelink resources and transmit, based at leastin part on the configuration message, a request for resources within theavailable sidelink resources, the request indicating the identifier anda BSR configured based at least in part on whether the request forresources is associated with the second RAT or both the first RAT andthe second RAT.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for receiving downlinkcontrol information (DCI) in a control channel. Some examples of themethod, apparatuses, and non-transitory computer-readable mediumdescribed herein may further include operations, features, means, orinstructions for descrambling the DCI using the identifier to obtain aresource grant allocating resources within the available sidelinkresources. Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for performing the sidelinkcommunications using the allocated resources.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the identifier includes afirst identifier associated with the first RAT and a second identifierassociated with the second RAT.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for receiving DCI in acontrol channel. Some examples of the method, apparatuses, andnon-transitory computer-readable medium described herein may furtherinclude operations, features, means, or instructions for descramblingthe DCI using the first identifier for determining whether the DCIincludes a resource grant allocating resources to the first RAT. Someexamples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for descrambling the DCIusing the second identifier for determining whether the DCI includes aresource grant allocating resources to the second RAT.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the identifier includes afirst identifier associated with the second RAT and a second identifierassociated with the second RAT.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for receiving DCI in acontrol channel. Some examples of the method, apparatuses, andnon-transitory computer-readable medium described herein may furtherinclude operations, features, means, or instructions for descramblingthe DCI using the first identifier for determining whether the DCIincludes a resource grant allocating resources to the second RATassociated with a first transmission type. Some examples of the method,apparatuses, and non-transitory computer-readable medium describedherein may further include operations, features, means, or instructionsfor descrambling the DCI using the second identifier for determiningwhether the DCI includes a resource grant allocating resources to thesecond RAT associated with a second transmission type.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the sidelink informationmessage indicates a transmission type, a traffic profile, a quality ofservice indicator, a service type indicator, or any combination thereof,for the sidelink communications.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the BSR indicates a bufferstatus for the first RAT and a buffer status for the second RAT.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the configuration messageindicates a mapping assignment for a logical channel associated with thefirst RAT or the second RAT.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the identifier may be atleast one of a logical channel identifier (LCID) or a radio networktemporary identifier (RNTI). In some examples of the method,apparatuses, and non-transitory computer-readable medium describedherein, the configuration message may be a radio resource control (RRC)message.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the message may be a SIBmessage that may be broadcast by the base station. In some examples ofthe method, apparatuses, and non-transitory computer-readable mediumdescribed herein, the first RAT may be an LTE RAT and the second RAT maybe a NR RAT.

A method of wireless communication at a base station is described. Themethod may include receiving a sidelink information message from a UEusing a first RAT indicating that sidelink communications are to beperformed using a second RAT or both the first RAT and the second RATand transmitting a configuration message to the UE that comprises anidentifier for the sidelink communications and an indication ofavailable sidelink resources. The method may also include receiving,based at least in part on the configuration message, a request forresources within the available sidelink resources, the requestindicating the identifier and a BSR configured based at least in part onwhether the request for resources is associated with the second RAT orboth the first RAT and the second RAT.

An apparatus for wireless communication at a base station is described.The apparatus may include a processor, memory in electroniccommunication with the processor, and instructions stored in the memory.The instructions may be executable by the processor to cause theapparatus to receive a sidelink information message from a UE using afirst RAT indicating that sidelink communications are to be performedusing a second RAT or both the first RAT and the second RAT and transmita configuration message to the UE that comprises an identifier for thesidelink communications and an indication of available sidelinkresources The instructions may also be executable by the processor toreceive, based at least in part on the configuration message, a requestfor resources within the available sidelink resources, the requestindicating the identifier and a BSR configured based at least in part onwhether the request for resources is associated with the second RAT orboth the first RAT and the second RAT.

Another apparatus for wireless communication at a base station isdescribed. The apparatus may include means for receiving a sidelinkinformation message from a UE using a first RAT indicating that sidelinkcommunications are to be performed using a second RAT or both the firstRAT and the second RAT and means for transmitting a configurationmessage to the UE that comprises an identifier for the sidelinkcommunications and an indication of available sidelink resources. Theapparatus may also include means for receiving, based at least in parton the configuration message, a request for resources within theavailable sidelink resources, the request indicating the identifier anda BSR configured based at least in part on whether the request forresources is associated with the second RAT or both the first RAT andthe second RAT.

A non-transitory computer-readable medium storing code for wirelesscommunication at a base station is described. The code may includeinstructions executable by a processor to receive a sidelink informationmessage from a UE using a first RAT indicating that sidelinkcommunications are to be performed using a second RAT or both the firstRAT and the second RAT and transmit a configuration message to the UEthat comprises an identifier for the sidelink communications and anindication of available sidelink resources. The code may also includeinstructions executable by the processor to receive, based at least inpart on the configuration message, a request for resources within theavailable sidelink resources, the request indicating the identifier anda BSR configured based at least in part on whether the request forresources is associated with the second RAT or both the first RAT andthe second RAT.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for generating a resourcegrant allocating resources within the available sidelink resources toperform the sidelink communications. Some examples of the method,apparatuses, and non-transitory computer-readable medium describedherein may further include operations, features, means, or instructionsfor scrambling the resource grant using the identifier to generate ascrambled resource grant. Some examples of the method, apparatuses, andnon-transitory computer-readable medium described herein may furtherinclude operations, features, means, or instructions for transmitting,in a control channel, DCI that comprises the scrambled resource grant.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the identifier includes afirst identifier associated with the first RAT and a second identifierassociated with the second RAT.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for generating a firstresource grant allocating first resources within the available sidelinkresources to the first RAT and a second resource grant allocating secondresources within the available sidelink resources to the second RAT.Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for scrambling the firstresource grant using the first identifier to generate a first scrambledresource grant. Some examples of the method, apparatuses, andnon-transitory computer-readable medium described herein may furtherinclude operations, features, means, or instructions for scrambling thesecond resource grant using the second identifier to generate a secondscrambled resource grant. Some examples of the method, apparatuses, andnon-transitory computer-readable medium described herein may furtherinclude operations, features, means, or instructions for transmitting,in a control channel, DCI that comprises the first scrambled resourcegrant and the second scrambled resource grant.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the identifier includes afirst identifier associated with the second RAT and a second identifierassociated with the second RAT.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for generating a firstresource grant allocating first resources within the available sidelinkresources to the second RAT and a second resource grant allocatingsecond resources within the available sidelink resources to the secondRAT. Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for scrambling the firstresource grant using the first identifier to generate a first scrambledresource grant. Some examples of the method, apparatuses, andnon-transitory computer-readable medium described herein may furtherinclude operations, features, means, or instructions for scrambling thesecond resource grant using the second identifier to generate a secondscrambled resource grant. Some examples of the method, apparatuses, andnon-transitory computer-readable medium described herein may furtherinclude operations, features, means, or instructions for transmitting,in a control channel, downlink control information (DCI) that comprisesthe first scrambled resource grant and the second scrambled resourcegrant.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the BSR indicates a bufferstatus for the first RAT and a buffer status for the second RAT.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the sidelink informationmessage identifies a transmission type, a traffic profile, a quality ofservice indicator, a service type indicator, or any combination thereof,for the sidelink communications.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the identifier may be atleast one of a LCID or a RNTI. In some examples of the method,apparatuses, and non-transitory computer-readable medium describedherein, the configuration message may be an RRC message. Some examplesof the method, apparatuses, and non-transitory computer-readable mediumdescribed herein may further include operations, features, means, orinstructions for transmitting a SIB message indicating support forallocating resources for sidelink communications using the first RAT andthe second RAT.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the first RAT may be an LTERAT and the second RAT may be a NR RAT.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example of a wireless communications system thatsupports multi-radio access technology (RAT) scheduling of sidelinkinterface in accordance with aspects of the present disclosure.

FIG. 2 illustrates an example of a wireless communication system thatsupports multi-RAT scheduling of sidelink interface in accordance withaspects of the present disclosure.

FIG. 3 illustrates an example of a flowchart that supports multi-RATscheduling of sidelink interface in accordance with aspects of thepresent disclosure.

FIG. 4 illustrates an example of protocol stack configurations thatsupports multi-RAT scheduling of sidelink interface in accordance withaspects of the present disclosure.

FIG. 5 illustrates an example of a process that supports multi-RATscheduling of sidelink interface in accordance with aspects of thepresent disclosure.

FIGS. 6 and 7 show block diagrams of devices that supports multi-RATscheduling of sidelink interface in accordance with aspects of thepresent disclosure.

FIG. 8 show a block diagram of a device that supports multi-RATscheduling of sidelink interface in accordance with aspects of thepresent disclosure.

FIG. 9 illustrates a block diagram of a system including a userequipment (UE) that supports multi-RAT scheduling of sidelink interfacein accordance with aspects of the present disclosure.

FIGS. 10 and 11 show block diagrams of devices that supports multi-RATscheduling of sidelink interface in accordance with aspects of thepresent disclosure.

FIG. 12 show a block diagram of a device that supports multi-RATscheduling of sidelink interface in accordance with aspects of thepresent disclosure.

FIG. 13 illustrates a block diagram of a system including a base stationthat supports multi-RAT scheduling of sidelink interface in accordancewith aspects of the present disclosure.

FIGS. 14 through 17 illustrate methods for multi-RAT scheduling ofsidelink interface in accordance with aspects of the present disclosure.

DETAILED DESCRIPTION

The described techniques relate to improved methods, systems, devices,and apparatuses that support multi-radio access technology (RAT)scheduling of sidelink interface. Generally, the described techniquesprovide an efficient mechanism that supports evolving PC5 interfacesbetween different RATs (e.g., a first RAT such as a Long Term Evolution(LTE) RAT) and a second RAT such as a new radio (NR) RAT). In someaspects, a user equipment (UE) may receive a signal indicating that abase station supports the allocation of sidelink resources on multipleRATs, and the UE may coordinate with the base station to obtain sidelinkresources using more than one RAT.

Some wireless communication systems support sidelink communications.Broadly, sidelink communications include communications between wirelessdevices, such as between UEs. Sidelink communications, such as thoseperformed using PC5 interfaces, may be utilized in a device-to-device(D2D) communication scenario, in a vehicle-based communication scenario(e.g., vehicle to everything (V2X), vehicle to vehicle (V2V), etc.,communications), and the like. Generally, sidelink communications can beeither network-assisted or autonomous. Network-assisted sidelinkcommunications typically include a base station allocating sidelinkresources (e.g., resources in the time, frequency, and/or spatialdomain) to the UEs to use for sidelink communications. Autonomoussidelink communications are typically associated with a resource poolthat is made available to UEs to select the sidelink resources from.

Wireless communication systems may be heterogeneous in that multipleRATs may be deployed. For example, an LTE RAT may be deployed in placeof, alongside, or overlapping with a NR RAT. However, deploying multipleRATs also has an associated increase in cost, e.g., such as financialcost in terms of additional equipment, cost in terms of over the airresources, cost in terms of potential conflicts or collisions, and thelike. Moreover, such separate deployments may not necessarily supportscheduling sidelink communication resources to UEs that are equipped tosupport sidelink communications using different RATs.

Aspects of the disclosure are initially described in the context of awireless communications system and provide for implementation of anefficient technique that allows a base station to support allocatingsidelink resources to UEs using different RATs. For example, the basestation may be configured to support scheduling of sidelink resourcesfor a first RAT (e.g., an LTE RAT) and a second RAT (e.g., a NR RAT). Insome examples, the base station may be configured to support schedulingof sidelink resources for three or more RATs. Accordingly, the basestation may broadcast a signal (e.g., in a system information block(SIB) message) that informs or otherwise indicates to the UEs within itscoverage area that supports dual, or more, RAT sidelink scheduling. Thebase station may primarily support wireless communications with the UEsusing the first RAT.

A UE may determine that it wants to perform sidelink communicationsusing the second RAT or using both of the first RAT and the second RAT.Accordingly, the UE may transmit a sidelink information message to thebase station that includes or otherwise conveys an indication that theUE wants to perform the sidelink communications using the second RAT orboth of the first RAT and the second RAT. In some aspects, the sidelinkinformation message may be transmitted to the base station using thefirst RAT. In some aspects, the sidelink information message may includeadditional information, such as whether the sidelink communications arefor normal or high priority communications, a quality-of-service (QoS)indicator for the sidelink communications, a transmissions typeindication, a service type indicator, and the like.

The base station may receive the sidelink information message andrespond with a configuration message, e.g., using radio resource control(RRC) signaling, to the UE. In some aspects, the RRC signaling mayprovide configuration information to the UE, such as an identifier forthe sidelink communications, an indication of available sidelinkresources, and the like. The UE may respond by transmitting a requestfor resources to the base station. Generally, the resource request mayinclude one or more buffer status reports (BSRs) that are configuredbased on whether the resource request is for sidelink resources usingthe second RAT or both of the first RAT and the second RAT. For example,a first BSR may be included in the resource request identifyinginformation to be communicated using the first RAT and a second BSR maybe included in the resource request identifying information to becommunicated using the second RAT. In some aspects, the identifierreceived in a configuration message from the base station (e.g., the RRCsignaling) may be included in the BSRs. Accordingly, the base stationmay respond by transmitting a scheduling grant for sidelink resourcesusing the second RAT or using the first RAT and the second RAT (e.g., asis indicated in the resource request and the sidelink informationmessage). The UE may use the sidelink resources from the schedulinggrant to perform the sidelink communications with other UEs.

Aspects of the disclosure are further illustrated by and described withreference to apparatus diagrams, system diagrams, and flowcharts thatrelate to multi-RAT scheduling of sidelink interface.

FIG. 1 illustrates an example of a wireless communications system 100that supports multi-RAT scheduling of a sidelink interface in accordancewith aspects of the present disclosure. The wireless communicationssystem 100 includes base stations 105, UEs 115, and a core network 130.In some examples, the wireless communications system 100 may be an LTEnetwork, an LTE-Advanced (LTE-A) network, an LTE-A Pro network, or a NRnetwork. In some cases, wireless communications system 100 may supportenhanced broadband communications, ultra-reliable (e.g., missioncritical) communications, low latency communications, or communicationswith low-cost and low-complexity devices.

Base stations 105 may wirelessly communicate with UEs 115 via one ormore base station antennas. Base stations 105 described herein mayinclude or may be referred to by those skilled in the art as a basetransceiver station, a radio base station, an access point, a radiotransceiver, a NodeB, an eNodeB (eNB), a next-generation Node B orgiga-nodeB (either of which may be referred to as a gNB), a Home NodeB,a Home eNodeB, or some other suitable terminology. Wirelesscommunications system 100 may include base stations 105 of differenttypes (e.g., macro or small cell base stations). The UEs 115 describedherein may be able to communicate with various types of base stations105 and network equipment including macro eNBs, small cell eNBs, gNBs,relay base stations, and the like.

Each base station 105 may be associated with a particular geographiccoverage area 110 in which communications with various UEs 115 issupported. Each base station 105 may provide communication coverage fora respective geographic coverage area 110 via communication links 125,and communication links 125 between a base station 105 and a UE 115 mayutilize one or more carriers. Communication links 125 shown in wirelesscommunications system 100 may include uplink transmissions from a UE 115to a base station 105, or downlink transmissions from a base station 105to a UE 115. Downlink transmissions may also be called forward linktransmissions while uplink transmissions may also be called reverse linktransmissions.

The geographic coverage area 110 for a base station 105 may be dividedinto sectors making up only a portion of the geographic coverage area110, and each sector may be associated with a cell. For example, eachbase station 105 may provide communication coverage for a macro cell, asmall cell, a hot spot, or other types of cells, or various combinationsthereof. In some examples, a base station 105 may be movable andtherefore provide communication coverage for a moving geographiccoverage area 110. In some examples, different geographic coverage areas110 associated with different technologies may overlap. Overlappinggeographic coverage areas 110 associated with different technologies maybe supported by the same base station 105 or by different base stations105. The wireless communications system 100 may include, for example, aheterogeneous LTE/LTE-A/LTE-A Pro or NR network in which different typesof base stations 105 provide coverage for various geographic coverageareas 110.

The term “cell” refers to a logical communication entity used forcommunication with a base station 105 (e.g., over a carrier), and may beassociated with an identifier for distinguishing neighboring cells(e.g., a physical cell identifier (PCID), a virtual cell identifier(VCID)) operating via the same or a different carrier. In some examples,a carrier may support multiple cells, and different cells may beconfigured according to different protocol types (e.g., machine-typecommunication (MTC), narrowband Internet-of-Things (NB-IoT), enhancedmobile broadband (eMBB), or others) that may provide access fordifferent types of devices. In some cases, the term “cell” may refer toa portion of a geographic coverage area 110 (e.g., a sector) over whichthe logical entity operates.

UEs 115 may be dispersed throughout the wireless communications system100, and each UE 115 may be stationary or mobile. A UE 115 may also bereferred to as a mobile device, a wireless device, a remote device, ahandheld device, or a subscriber device, or some other suitableterminology, where the “device” may also be referred to as a unit, astation, a terminal, or a client. A UE 115 may also be a personalelectronic device such as a cellular phone, a personal digital assistant(PDA), a tablet computer, a laptop computer, or a personal computer. Insome examples, a UE 115 may also refer to a wireless local loop (WLL)station, an Internet of Things (IoT) device, an Internet of Everything(IoE) device, or an MTC device, or the like, which may be implemented invarious articles such as appliances, vehicles, meters, or the like.

Some UEs 115, such as MTC or IoT devices, may be low cost or lowcomplexity devices, and may provide for automated communication betweenmachines (e.g., via Machine-to-Machine (M2M) communication). M2Mcommunication or MTC may refer to data communication technologies thatallow devices to communicate with one another or a base station 105without human intervention. In some examples, M2M communication or MTCmay include communications from devices that integrate sensors or metersto measure or capture information and relay that information to acentral server or application program that can make use of theinformation or present the information to humans interacting with theprogram or application. Some UEs 115 may be designed to collectinformation or enable automated behavior of machines. Examples ofapplications for MTC devices include smart metering, inventorymonitoring, water level monitoring, equipment monitoring, healthcaremonitoring, wildlife monitoring, weather and geological eventmonitoring, fleet management and tracking, remote security sensing,physical access control, and transaction-based business charging.

Some UEs 115 may be configured to employ operating modes that reducepower consumption, such as half-duplex communications (e.g., a mode thatsupports one-way communication via transmission or reception, but nottransmission and reception simultaneously). In some examples half-duplexcommunications may be performed at a reduced peak rate. Other powerconservation techniques for UEs 115 include entering a power saving“deep sleep” mode when not engaging in active communications, oroperating over a limited bandwidth (e.g., according to narrowbandcommunications). In some cases, UEs 115 may be designed to supportcritical functions (e.g., mission critical functions), and a wirelesscommunications system 100 may be configured to provide ultra-reliablecommunications for these functions.

In some cases, a UE 115 may also be able to communicate directly withother UEs 115 (e.g., using a peer-to-peer (P2P) or device-to-device(D2D) protocol). One or more of a group of UEs 115 utilizing D2Dcommunications may be within the geographic coverage area 110 of a basestation 105. Other UEs 115 in such a group may be outside the geographiccoverage area 110 of a base station 105 or be otherwise unable toreceive transmissions from a base station 105. In some cases, groups ofUEs 115 communicating via D2D communications may utilize a one-to-many(1:M) system in which each UE 115 transmits to every other UE 115 in thegroup. In some cases, a base station 105 facilitates the scheduling ofresources for D2D communications. In other cases, D2D communications arecarried out between UEs 115 without the involvement of a base station105.

Base stations 105 may communicate with the core network 130 and with oneanother. For example, base stations 105 may interface with the corenetwork 130 through backhaul links 132 (e.g., via an S1 or otherinterface). Base stations 105 may communicate with one another overbackhaul links 134 (e.g., via an X2 or other interface) either directly(e.g., directly between base stations 105) or indirectly (e.g., via corenetwork 130).

The core network 130 may provide user authentication, accessauthorization, tracking, Internet Protocol (IP) connectivity, and otheraccess, routing, or mobility functions. The core network 130 may be anevolved packet core (EPC), which may include at least one mobilitymanagement entity (MME), at least one serving gateway (S-GW), and atleast one Packet Data Network (PDN) gateway (P-GW). The MME may managenon-access stratum (e.g., control plane) functions such as mobility,authentication, and bearer management for UEs 115 served by basestations 105 associated with the EPC. User IP packets may be transferredthrough the S-GW, which itself may be connected to the P-GW. The P-GWmay provide IP address allocation as well as other functions. The P-GWmay be connected to the network operators IP services. The operators IPservices may include access to the Internet, Intranet(s), an IPMultimedia Subsystem (IMS), or a Packet-Switched (PS) Streaming Service.

At least some of the network devices, such as a base station 105, mayinclude subcomponents such as an access network entity, which may be anexample of an access node controller (ANC). Each access network entitymay communicate with UEs 115 through a number of other access networktransmission entities, which may be referred to as a radio head, a smartradio head, or a transmission/reception point (TRP). In someconfigurations, various functions of each access network entity or basestation 105 may be distributed across various network devices (e.g.,radio heads and access network controllers) or consolidated into asingle network device (e.g., a base station 105).

Wireless communications system 100 may operate using one or morefrequency bands, typically in the range of 300 MHz to 300 GHz.Generally, the region from 300 MHz to 3 GHz is known as the ultra-highfrequency (UHF) region or decimeter band, since the wavelengths rangefrom approximately one decimeter to one meter in length. UHF waves maybe blocked or redirected by buildings and environmental features.However, the waves may penetrate structures sufficiently for a macrocell to provide service to UEs 115 located indoors. Transmission of UHFwaves may be associated with smaller antennas and shorter range (e.g.,less than 100 km) compared to transmission using the smaller frequenciesand longer waves of the high frequency (HF) or very high frequency (VHF)portion of the spectrum below 300 MHz.

Wireless communications system 100 may also operate in a super highfrequency (SHF) region using frequency bands from 3 GHz to 30 GHz, alsoknown as the centimeter band. The SHF region includes bands such as the5 GHz industrial, scientific, and medical (ISM) bands, which may be usedopportunistically by devices that can tolerate interference from otherusers.

Wireless communications system 100 may also operate in an extremely highfrequency (EHF) region of the spectrum (e.g., from 30 GHz to 300 GHz),also known as the millimeter band. In some examples, wirelesscommunications system 100 may support millimeter wave (mmW)communications between UEs 115 and base stations 105, and EHF antennasof the respective devices may be even smaller and more closely spacedthan UHF antennas. In some cases, this may facilitate use of antennaarrays within a UE 115. However, the propagation of EHF transmissionsmay be subject to even greater atmospheric attenuation and shorter rangethan SHF or UHF transmissions. Techniques disclosed herein may beemployed across transmissions that use one or more different frequencyregions, and designated use of bands across these frequency regions maydiffer by country or regulating body.

In some cases, wireless communications system 100 may utilize bothlicensed and unlicensed radio frequency spectrum bands. For example,wireless communications system 100 may employ License Assisted Access(LAA), LTE-Unlicensed (LTE-U) radio access technology, or NR technologyin an unlicensed band such as the 5 GHz ISM band. When operating inunlicensed radio frequency spectrum bands, wireless devices such as basestations 105 and UEs 115 may employ listen-before-talk (LBT) proceduresto ensure a frequency channel is clear before transmitting data. In somecases, operations in unlicensed bands may be based on a CA configurationin conjunction with CCs operating in a licensed band (e.g., LAA).Operations in unlicensed spectrum may include downlink transmissions,uplink transmissions, peer-to-peer transmissions, or a combination ofthese. Duplexing in unlicensed spectrum may be based on frequencydivision duplexing (FDD), time division duplexing (TDD), or acombination of both.

In some examples, base station 105 or UE 115 may be equipped withmultiple antennas, which may be used to employ techniques such astransmit diversity, receive diversity, multiple-input multiple-output(MIMO) communications, or beamforming. For example, wirelesscommunications system 100 may use a transmission scheme between atransmitting device (e.g., a base station 105) and a receiving device(e.g., a UE 115), where the transmitting device is equipped withmultiple antennas and the receiving devices are equipped with one ormore antennas. MIMO communications may employ multipath signalpropagation to increase the spectral efficiency by transmitting orreceiving multiple signals via different spatial layers, which may bereferred to as spatial multiplexing. The multiple signals may, forexample, be transmitted by the transmitting device via differentantennas or different combinations of antennas. Likewise, the multiplesignals may be received by the receiving device via different antennasor different combinations of antennas. Each of the multiple signals maybe referred to as a separate spatial stream and may carry bitsassociated with the same data stream (e.g., the same codeword) ordifferent data streams. Different spatial layers may be associated withdifferent antenna ports used for channel measurement and reporting. MIMOtechniques include single-user MIMO (SU-MIMO) where multiple spatiallayers are transmitted to the same receiving device, and multiple-userMIMO (MU-MIMO) where multiple spatial layers are transmitted to multipledevices.

Beamforming, which may also be referred to as spatial filtering,directional transmission, or directional reception, is a signalprocessing technique that may be used at a transmitting device or areceiving device (e.g., a base station 105 or a UE 115) to shape orsteer an antenna beam (e.g., a transmit beam or receive beam) along aspatial path between the transmitting device and the receiving device.Beamforming may be achieved by combining the signals communicated viaantenna elements of an antenna array such that signals propagating atparticular orientations with respect to an antenna array experienceconstructive interference while others experience destructiveinterference. The adjustment of signals communicated via the antennaelements may include a transmitting device or a receiving deviceapplying certain amplitude and phase offsets to signals carried via eachof the antenna elements associated with the device. The adjustmentsassociated with each of the antenna elements may be defined by abeamforming weight set associated with a particular orientation (e.g.,with respect to the antenna array of the transmitting device orreceiving device, or with respect to some other orientation).

In one example, a base station 105 may use multiple antennas or antennaarrays to conduct beamforming operations for directional communicationswith a UE 115. For instance, some signals (e.g., synchronizationsignals, reference signals, beam selection signals, or other controlsignals) may be transmitted by a base station 105 multiple times indifferent directions, which may include a signal being transmittedaccording to different beamforming weight sets associated with differentdirections of transmission. Transmissions in different beam directionsmay be used to identify (e.g., by the base station 105 or a receivingdevice, such as a UE 115) a beam direction for subsequent transmissionand/or reception by the base station 105. Some signals, such as datasignals associated with a particular receiving device, may betransmitted by a base station 105 in a single beam direction (e.g., adirection associated with the receiving device, such as a UE 115). Insome examples, the beam direction associated with transmissions along asingle beam direction may be determined based at least in part on asignal that was transmitted in different beam directions. For example, aUE 115 may receive one or more of the signals transmitted by the basestation 105 in different directions, and the UE 115 may report to thebase station 105 an indication of the signal it received with a highestsignal quality, or an otherwise acceptable signal quality. Althoughthese techniques are described with reference to signals transmitted inone or more directions by a base station 105, a UE 115 may employsimilar techniques for transmitting signals multiple times in differentdirections (e.g., for identifying a beam direction for subsequenttransmission or reception by the UE 115) or transmitting a signal in asingle direction (e.g., for transmitting data to a receiving device).

A receiving device (e.g., a UE 115, which may be an example of a mmWreceiving device) may try multiple receive beams when receiving varioussignals from the base station 105, such as synchronization signals,reference signals, beam selection signals, or other control signals. Forexample, a receiving device may try multiple receive directions byreceiving via different antenna subarrays, by processing receivedsignals according to different antenna subarrays, by receiving accordingto different receive beamforming weight sets applied to signals receivedat a plurality of antenna elements of an antenna array, or by processingreceived signals according to different receive beamforming weight setsapplied to signals received at a plurality of antenna elements of anantenna array, any of which may be referred to as “listening” accordingto different receive beams or receive directions. In some examples areceiving device may use a single receive beam to receive along a singlebeam direction (e.g., when receiving a data signal). The single receivebeam may be aligned in a beam direction determined based at least inpart on listening according to different receive beam directions (e.g.,a beam direction determined to have a highest signal strength, highestsignal-to-noise ratio, or otherwise acceptable signal quality based atleast in part on listening according to multiple beam directions).

In some cases, the antennas of a base station 105 or UE 115 may belocated within one or more antenna arrays, which may support MIMOoperations, or transmit or receive beamforming. For example, one or morebase station antennas or antenna arrays may be co-located at an antennaassembly, such as an antenna tower. In some cases, antennas or antennaarrays associated with a base station 105 may be located in diversegeographic locations. A base station 105 may have an antenna array witha number of rows and columns of antenna ports that the base station 105may use to support beamforming of communications with a UE 115.Likewise, a UE 115 may have one or more antenna arrays that may supportvarious MIMO or beamforming operations.

In some cases, wireless communications system 100 may be a packet-basednetwork that operate according to a layered protocol stack. In the userplane, communications at the bearer or Packet Data Convergence Protocol(PDCP) layer may be IP-based. A Radio Link Control (RLC) layer may insome cases perform packet segmentation and reassembly to communicateover logical channels. A Medium Access Control (MAC) layer may performpriority handling and multiplexing of logical channels into transportchannels. The MAC layer may also use hybrid automatic repeat request(HARQ) to provide retransmission at the MAC layer to improve linkefficiency. In the control plane, the Radio Resource Control (RRC)protocol layer may provide establishment, configuration, and maintenanceof an RRC connection between a UE 115 and a base station 105 or corenetwork 130 supporting radio bearers for user plane data. At thePhysical (PHY) layer, transport channels may be mapped to physicalchannels.

In some cases, UEs 115 and base stations 105 may support retransmissionsof data to increase the likelihood that data is received successfully.HARQ feedback is one technique of increasing the likelihood that data isreceived correctly over a communication link 125. HARQ may include acombination of error detection (e.g., using a cyclic redundancy check(CRC)), forward error correction (FEC), and retransmission (e.g.,automatic repeat request (ARQ)). HARQ may improve throughput at the MAClayer in poor radio conditions (e.g., signal-to-noise conditions). Insome cases, a wireless device may support same-slot HARQ feedback, wherethe device may provide HARQ feedback in a specific slot for datareceived in a previous symbol in the slot. In other cases, the devicemay provide HARQ feedback in a subsequent slot, or according to someother time interval.

Time intervals in LTE or NR may be expressed in multiples of a basictime unit, which may, for example, refer to a sampling period ofT_(s)=1/30,720,000 seconds. Time intervals of a communications resourcemay be organized according to radio frames each having a duration of 10milliseconds (ms), where the frame period may be expressed asT_(f)=307,200 T_(s). The radio frames may be identified by a systemframe number (SFN) ranging from 0 to 1023. Each frame may include 10subframes numbered from 0 to 9, and each subframe may have a duration of1 ms. A subframe may be further divided into 2 slots each having aduration of 0.5 ms, and each slot may contain 6 or 7 modulation symbolperiods (e.g., depending on the length of the cyclic prefix prepended toeach symbol period). Excluding the cyclic prefix, each symbol period maycontain 2048 sampling periods. In some cases, a subframe may be thesmallest scheduling unit of the wireless communications system 100 andmay be referred to as a transmission time interval (TTI). In othercases, a smallest scheduling unit of the wireless communications system100 may be shorter than a subframe or may be dynamically selected (e.g.,in bursts of shortened TTIs (sTTIs) or in selected component carriersusing sTTIs).

In some wireless communications systems, a slot may further be dividedinto multiple mini-slots containing one or more symbols. In someinstances, a symbol of a mini-slot or a mini-slot may be the smallestunit of scheduling. Each symbol may vary in duration depending on thesubcarrier spacing or frequency band of operation, for example. Further,some wireless communications systems may implement slot aggregation inwhich multiple slots or mini-slots are aggregated together and used forcommunication between a UE 115 and a base station 105.

The term “carrier” refers to a set of radio frequency spectrum resourceshaving a defined physical layer structure for supporting communicationsover a communication link 125. For example, a carrier of a communicationlink 125 may include a portion of a radio frequency spectrum band thatis operated according to physical layer channels for a given radioaccess technology. Each physical layer channel may carry user data,control information, or other signaling. A carrier may be associatedwith a pre-defined frequency channel (e.g., an E-UTRA absolute radiofrequency channel number (EARFCN)) and may be positioned according to achannel raster for discovery by UEs 115. Carriers may be downlink oruplink (e.g., in an FDD mode), or be configured to carry downlink anduplink communications (e.g., in a TDD mode). In some examples, signalwaveforms transmitted over a carrier may be made up of multiplesub-carriers (e.g., using multi-carrier modulation (MCM) techniques suchas OFDM or DFT-s-OFDM).

The organizational structure of the carriers may be different fordifferent radio access technologies (e.g., LTE, LTE-A, LTE-A Pro, NR,etc.). For example, communications over a carrier may be organizedaccording to TTIs or slots, each of which may include user data as wellas control information or signaling to support decoding the user data. Acarrier may also include dedicated acquisition signaling (e.g.,synchronization signals or system information, etc.) and controlsignaling that coordinates operation for the carrier. In some examples(e.g., in a carrier aggregation configuration), a carrier may also haveacquisition signaling or control signaling that coordinates operationsfor other carriers.

Physical channels may be multiplexed on a carrier according to varioustechniques. A physical control channel and a physical data channel maybe multiplexed on a downlink carrier, for example, using time divisionmultiplexing (TDM) techniques, frequency division multiplexing (FDM)techniques, or hybrid TDM-FDM techniques. In some examples, controlinformation transmitted in a physical control channel may be distributedbetween different control regions in a cascaded manner (e.g., between acommon control region or common search space and one or more UE-specificcontrol regions or UE-specific search spaces).

A carrier may be associated with a particular bandwidth of the radiofrequency spectrum, and in some examples the carrier bandwidth may bereferred to as a “system bandwidth” of the carrier or the wirelesscommunications system 100. For example, the carrier bandwidth may be oneof a number of predetermined bandwidths for carriers of a particularradio access technology (e.g., 1.4, 3, 5, 10, 15, 20, 40, or 80 MHz). Insome examples, each served UE 115 may be configured for operating overportions or all of the carrier bandwidth. In other examples, some UEs115 may be configured for operation using a narrowband protocol typethat is associated with a predefined portion or range (e.g., set ofsubcarriers or RBs) within a carrier (e.g., “in-band” deployment of anarrowband protocol type).

In a system employing MCM techniques, a resource element may consist ofone symbol period (e.g., a duration of one modulation symbol) and onesubcarrier, where the symbol period and subcarrier spacing are inverselyrelated. The number of bits carried by each resource element may dependon the modulation scheme (e.g., the order of the modulation scheme).Thus, the more resource elements that a UE 115 receives and the higherthe order of the modulation scheme, the higher the data rate may be forthe UE 115. In MIMO systems, a wireless communications resource mayrefer to a combination of a radio frequency spectrum resource, a timeresource, and a spatial resource (e.g., spatial layers), and the use ofmultiple spatial layers may further increase the data rate forcommunications with a UE 115.

Devices of the wireless communications system 100 (e.g., base stations105 or UEs 115) may have a hardware configuration that supportscommunications over a particular carrier bandwidth or may beconfigurable to support communications over one of a set of carrierbandwidths. In some examples, the wireless communications system 100 mayinclude base stations 105 and/or UEs 115 that can support simultaneouscommunications via carriers associated with more than one differentcarrier bandwidth.

Wireless communications system 100 may support communication with a UE115 on multiple cells or carriers, a feature which may be referred to ascarrier aggregation (CA) or multi-carrier operation. A UE 115 may beconfigured with multiple downlink CCs and one or more uplink CCsaccording to a carrier aggregation configuration. Carrier aggregationmay be used with both FDD and TDD component carriers.

In some cases, wireless communications system 100 may utilize enhancedcomponent carriers (eCCs). An eCC may be characterized by one or morefeatures including wider carrier or frequency channel bandwidth, shortersymbol duration, shorter TTI duration, or modified control channelconfiguration. In some cases, an eCC may be associated with a carrieraggregation configuration or a dual connectivity configuration (e.g.,when multiple serving cells have a suboptimal or non-ideal backhaullink). An eCC may also be configured for use in unlicensed spectrum orshared spectrum (e.g., where more than one operator is allowed to usethe spectrum). An eCC characterized by wide carrier bandwidth mayinclude one or more segments that may be utilized by UEs 115 that arenot capable of monitoring the whole carrier bandwidth or are otherwiseconfigured to use a limited carrier bandwidth (e.g., to conserve power).

In some cases, an eCC may utilize a different symbol duration than otherCCs, which may include use of a reduced symbol duration as compared withsymbol durations of the other CCs. A shorter symbol duration may beassociated with increased spacing between adjacent subcarriers. Adevice, such as a UE 115 or base station 105, utilizing eCCs maytransmit wideband signals (e.g., according to frequency channel orcarrier bandwidths of 20, 40, 60, 80 MHz, etc.) at reduced symboldurations (e.g., 16.67 microseconds). A TTI in eCC may consist of one ormultiple symbol periods. In some cases, the TTI duration (that is, thenumber of symbol periods in a TTI) may be variable.

Wireless communications systems such as an NR system may utilize anycombination of licensed, shared, and unlicensed spectrum bands, amongothers. The flexibility of eCC symbol duration and subcarrier spacingmay allow for the use of eCC across multiple spectrums. In someexamples, NR shared spectrum may increase spectrum utilization andspectral efficiency, specifically through dynamic vertical (e.g., acrossthe frequency domain) and horizontal (e.g., across the time domain)sharing of resources.

In some aspects, a UE 115 may receive a message indicating that a basestation 105 supports allocating resources for sidelink communicationsusing a first RAT and a second RAT that is different from the first RAT.The UE 115 may transmit a sidelink information message to the basestation 105 using the first RAT that indicates that sidelinkcommunications are to be performed using either the second RAT or boththe first RAT and the second RAT. The UE 115 may receive a configurationmessage from the base station 105 that comprises an identifier for thesidelink communications and an indication of available sidelinkresources. The UE 115 may transmit, based at least in part on theconfiguration message, a request for resources within the availablesidelink resources, the request indicating the identifier and a BSRconfigured based at least in part on whether the request for resourcesis associated with the second RAT or both the first RAT and the secondRAT.

In some aspects, a base station 105 may receive a sidelink informationmessage from a UE 115 using a first RAT indicating that sidelinkcommunications are to be performed using a second RAT or both the firstRAT and the second RAT. The base station 105 may transmit aconfiguration message to the UE 115 that comprises an identifier for thesidelink communications and an indication of available sidelinkresources. The base station 105 may receive, based at least in part onthe configuration message, a request for resources within the availablesidelink resources, the request indicating the identifier and a BSRconfigured based at least in part on whether the request for resourcesis associated with the second RAT or both the first RAT and the secondRAT.

FIG. 2 illustrates an example of a wireless communication system 200that supports multi-RAT scheduling of sidelink interface in accordancewith aspects of the present disclosure. In some examples, wirelesscommunication system 200 may implement aspects of wireless communicationsystem 100. Wireless communication system 200 may include a base station205, a UE 210, a UE 215, and a UE 220, which may be examples of thecorresponding devices described herein.

Generally, wireless communications systems may be deployed in a varietyof ways, which may be according to an associated RAT. For example, inone scenario, legacy base stations (such as LTE release 15 and the lowerbase stations) may be deployed adjacent to, but not overlapping, one ormore next-generation base stations (such as a 3rd Generation PartnershipProject (3GPP) release 16 and higher base stations, which may also bereferred to as NR base stations). In this scenario, a UE may only beable to support sidelink communications using the RAT that is associatedwith the base station to which the UE is connected.

As another example, a scenario may include next generation base stationsbeing deployed within the coverage area of a dual mode or a dualconnectivity base station (such as base station 205). In this scenario,the next generation base stations may be generically considered LTEconfigured base stations that may not support NR Uu interfacescheduling. The dual mode base station may support scheduling resources(e.g., such as sidelink resources) using more than one RAT. For example,the first RAT may refer to the legacy sidelink communication interfacesupported by an LTE base station (LTE PC5), for example an LTE release15 and lower base station, and the second RAT may refer to anext-generation sidelink communication interface (NR PC5) which may besupported by an enhanced base station, such as a 3GPP release 16 andhigher base station (e.g., a NR RAT base station). In some examples, thedual-mode base station may only be able to support sidelinkcommunication (PC5) using the second RAT (e.g., scheduling NR PC5resources), but may not support other communications included in theoverall second RAT (e.g., a NR Uu interface). In this context, the dualmode base station (e.g., base station 205) may primarily communicatewith UEs using the first RAT (e.g., using an LTE 3GPP release 16 orhigher), but may also support scheduling sidelink resources for the UEswithin its coverage area using the second RAT or using the first RAT andthe second RAT. Generally, in this context the sidelink resources may bescheduled using or via the first RAT.

As another example, a scenario may include next-generation base stationsbeing deployed, wherein one or more of the next-generation base stations(such as base station 205) are configured as dual mode base stationsthat primarily communicate using the second RAT, but also supportscheduling sidelink resources using the first RAT and the second RAT. Inthis scenario, the next generation base stations (e.g., NR basestations) may again primarily communicate with UEs using the second RATbut may also support scheduling sidelink communications using the firstRAT or using the first RAT and the second RAT.

Sidelink communications generally refer to direct communications betweenUEs, such as D2D communications, V2X communications, enhanced V2X(eV2X), and the like. Sidelink communications are typically performedvia a PC5 interface that enables direct communications between the UEs.However, the protocols/configurations for the PC5 interface may bedifferent for different RATs. For example, an LTE RAT may utilize afirst set of protocols, configurations, and the like, in order torequest and/or schedule sidelink resources for the LTE RAT PC5interface. Similarly, a NR RAT may utilize a second set of protocols,configurations, and the like, in order to request and reschedulesidelink resources for the NR RAT PC5 interface.

Accordingly, wireless communication system 200 may support wirelesscommunications using more than one RAT. For example, base station 205and one or more of UEs 210, 215, and/or 220, may be configured tosupport wireless communications using a first RAT (such as an LTE RAT)and to support sidelink communications using a second RAT (such as a NRRAT, a mmW RAT, and the like). In some aspects, base station 205 maycommunicate with UEs 210, 215, and/or 220, using a first RAT (e.g., anLTE RAT) in order to schedule the sidelink resources for a second RAT(e.g., a NR RAT). That is, wireless communication system 200 may beprimarily configured as a first RAT network but may support base station205 scheduling sidelink resources for UEs (e.g., UE 210, UE 215, and/orUE 220) to use to perform sidelink communications using the second RATor both of the first and second RATs.

In some aspects, base station 205 may advertise to the UEs within itscoverage area (such as UEs 210, 215, and/or 220) that it supportsscheduling sidelink resources using more than one RAT. For example, basestation 205 may be an LTE eNB configured for scheduling both LTE PC5 andNR-PC5. In some examples, wireless communication system 200 may notinclude a gNB, UEs 210, 215, and/or 220 may be outside a coverage rangeof a gNB of system 200, UEs 210, 215, and/or 220 may not haveestablished a connection with a gNB of system 200, or the like. In someaspects, base station 205 may broadcast a signal or message, such as ina SIB broadcast, that includes one or more bits, fields, and the like,that signals or otherwise conveys the indication that the base station205 supports scheduling sidelink resources using the first RAT and thesecond RAT. In some examples, support for scheduling sidelink resourcesfor the first RAT may be implicit (e.g., in that the base station 205 isprimarily configured to communicate using the first RAT), whereassupport for scheduling sidelink resources for the second RAT may beexplicit (e.g., such as setting a bit, a field, etc.) to provide theindication. Accordingly, the UEs within the coverage area base station205 may know ahead of time that base station 205 is available toschedule sidelink resources using more than one RAT.

In some aspects, a UE (such as UE 210 in this example) may determine toperform sidelink communications using one or more RATs. For example, UE210 may determine to perform sidelink communications using a first RAT(e.g., an LTE RAT) with UE 215 and perform sidelink communications usinga second RAT (e.g., an NR RAT) with UE 220. Accordingly, UE 210 maytransmit a sidelink information message (e.g., a SideLinkUEInfo message)to base station 205 that includes or otherwise conveys an indicationthat sidelink communications are to be performed using the second RAT orboth the first and second RATs.

In some aspects, the sidelink information message may utilize a bit, aflag, a field, and the like, to convey an indication that a resourcerequest is for the second RAT (and the first RAT, if applicable). Insome aspects, the bit, flag, field, and the like, may indicate that aresource request is for a NR or LTE carrier from a frequency list (e.g.,a sidelink V2X communication frequency list (SL-V2X-CommFreqList) or asidelink V2X communication transmission frequency list(SL-V2X-CommTxFreqList)). In some aspects, the sidelink informationmessage may include or otherwise provide an indication of a preferredtransmission type or radio resource type for the sidelinkcommunications, e.g., such as whether the sidelink communications arefor a normal TTI, an ultra-reliable/low-latency communications (URLLC),or both. In some aspects, the sidelink information message may includeor otherwise provide an indication of a QoS requirement for the sidelinkcommunications, e.g., such as a fifth generation (5G) quality indicator(5QI) requirement. In some aspects, the sidelink information message mayinclude or otherwise convey an indication of a service type for thesidelink communications, e.g., such as a provider service identifier(PSID), an intelligent transport systems application identifier(ITS-AID) message type indication, and the like. Base station 205 mayuse information provided in the indication of the transmission type andthe service type to ensure that appropriate sidelink resources areallocated to UE 210.

In some aspects, base station 205 may respond by transmitting aconfiguration message to UE 210 that includes or otherwise provides anindication of an identifier for the sidelink communications. Forexample, the configuration message may include an identifier fordifferent transmission types, such as a NR-V2X-RNTI for a normal TTItransmission type and a NR-V2X-URLLC-RNTI for an URLLC transmissiontype. As another example, the configuration message may include anidentifier associated with the RAT that the sidelink communications areto be performed on, e.g., such as a first identifier for the first RATand the second identifier for the second RAT.

In some examples, the configuration message may also include orotherwise provide an indication of a resource pool (e.g., such as listsof available sidelink resources). For example, the configuration messagemay provide an indication of shared or dedicated sidelink resources forthe second RAT (e.g., in a resource pool format). For example, theshared or dedicated sidelink resources may be shared or dedicated NR V2Xpools in a NR pool format. In some aspects, the configuration messagemay be communicated in RRC signaling or message (such as anRRCConnectionReconfiguration message). In some aspects, theconfiguration message may additionally include or otherwise provide anindication of a mapping assignment. The mapping assignment may map oneor more logical channels (e.g., per LCID) to the first RAT or the secondRAT. In some aspects, the mapping assignment may map the logical channelto a transmission type, e.g., a first LCID mapped to a normal TTItransmission type and a second LCID mapped to a URLLC transmission type.UE 210 may use the mapping assignment in configuring the BSR(s) for thesecond RAT.

In some aspects, UE 210 may respond by requesting sidelink resourcesfrom base station 205. For example, UE 210 may transmit to base station205 a request for resources within the available sidelink resourcesindicated in the configuration message. The resource request may includeor otherwise provide an indication of the identifier that was providedin the configuration message (e.g., a RNTI received in anRRCConnectionReconfiguration message). In some aspects, the resourcerequest may include one or more BSRs. For example, each of the one ormore BSRs may be configured based on whether the requested resources areassociated with the second RAT or are associated with the first RAT andthe second RAT. In some aspects, a BSR may be included for eachidentifier indicated in the configuration message, for each transmissiontype being communicated during the sidelink communications, and thelike. In some aspects, the resource request may be communicated as a MACcontrol element (CE) in an uplink communication from UE 210 to basestation 205.

In some aspects, the resource request may include a BSR configured forthe first RAT (e.g., a legacy LTE BSR) if the resource request is forsidelink resources for the first RAT (e.g., an LTE-PC5 resource). Insome aspects, the resource request may include an enhanced BSR if theresource request is for sidelink resources for the second RAT (e.g., foran NR-V2X resource or for a NR-V2X plus an LTE-PC5 resource). In someaspects, this may include UE 210 reusing a destination index mapping(e.g., the LCID mapping) and/or indicating a service type, such as PSIDor ITS-AID. In some aspects, the resource request may include theservice type indicator, such as PSID and/or ITS-AID, and/or thetransmission type indication, such as for a normal TTI transmission typeand/or a URLLC transmission type, that were indicated in the sidelinkinformation message.

In some aspects, base station 205 may respond to the resource requestwith the scheduling grant of sidelink resources. For example, basestation 205 may generate a resource grant that allocates resourceswithin the available sidelink resources, and scramble resource grantusing the identifier indicated in the configuration message. This maycreate a scrambled resource grant that is then transmitted in a DCI of acontrol channel to UE 210. In some aspects, UE 210 may receive the DCIin the control channel and descramble the DCI using the identifier. UE210 may obtain the resource grant that allocates the resources and thenuse those resources to perform the sidelink communications.

In some examples, multiple resource grants may be provided by basestation 205. For example, a resource grant may be provided for eachidentifier that was indicated in the configuration message. In the casewhere two identifiers were indicated, base station 205 may generateseparate resource grants for each identifier. Base station 205 mayscramble each resource grant using its associated identifier, e.g.,scramble a first resource grant using the first identifier and scramblea second resource grant using a second identifier). In some examples,each identifier may be associated with a different RAT, e.g., a firstidentifier associated with sidelink communications using the first RATand a second identifier associated with sidelink communications usingthe second RAT. In some aspects, each identifier may be associated withdifferent transmission types within the second RAT, e.g., such as afirst identifier associated with the first transmission type for thesecond RAT (e.g., NR-V2X-RNTI) and the second identifier associated witha second transmission type for the second RAT (e.g., NR-V2X-URLLC-RNTI).Accordingly, base station 205 may provide sidelink resource grantscorresponding to the identifiers indicated in the configuration message.

In some aspects, UE 210 may use the allocated sidelink resources toperform sidelink communications with UE 215 via the first RAT (e.g., theLTE RAT) and to perform sidelink communications with UE 220 via thesecond RAT (e.g., the NR RAT).

FIG. 3 illustrates an example of a flowchart 300 that supports multi-RATscheduling of sidelink interface in accordance with aspects of thepresent disclosure. In some examples, flowchart 300 may implementaspects of wireless communication systems 100/200. Aspects of flowchart300 may be implemented by a UE, which may be an example of thecorresponding device described herein.

At 305, the UE may receive a broadcast signal indicating support by abase station for LTE PC5 and NR PC5 scheduling, e.g., support forsidelink resource scheduling for LTE and NR RATs. In this example, theLTE PC5 interface may refer to a first RAT and the NR PC5 interface mayrefer to a second RAT. Generally, a PC5 interface has an associated, foreach RAT, set of protocols, configurations, and the like, for thesidelink communications between UEs. The broadcast signal may bereceived in a system information block message, in a synchronizationsignal message, and the like.

At 310, the UE may determine whether it wants to perform sidelinkcommunications using the second RAT or the second RAT and the first RAT.As one example, the UE may be configured generally to support the firstRAT for wireless communications, but also configured to support thesecond RAT, e.g., to support sidelink communications using the secondRAT. Accordingly, the UE may determine that it wants to perform sidelinkcommunications with the first UE that supports sidelink communicationsusing the second RAT. As another example, the UE may determine that itwants to perform sidelink communications with a first UE that isconfigured to support the first RAT and a second UE that is configuredto support the second RAT.

In some aspects, the determination of whether and how the UE requestssidelink resources may depend upon whether the UE wishes to performsidelink communications using just the second RAT or using the secondRAT and the first RAT.

In the situation where the UE is only requesting sidelink resources forthe second RAT, at 315 the UE may transmit a sidelink informationmessage to the base station using the first RAT, but that provides anindication that the sidelink communications are to be performed usingthe second RAT. In some aspects, the sidelink information message mayfurther include or otherwise provide an indication of a transmissiontype (e.g., normal TTI, URLLC, etc.), a traffic profile, a QoSindicator, a service type indicator, and the like, for the sidelinkcommunications using the second RAT. Generally, the transmission typemay correspond to a desired latency and type of resource allocation forthe sidelink communications, e.g., a normal TTI resource allocationversus a URLLC resource allocation, a mission critical (MiCR) resourceallocation versus a non-MiCR resource allocation, etc. Generally, thetraffic profile may refer to the type of traffic that is beingcommunicated using the sidelink communications, e.g., IP traffic versusvoice traffic, control traffic versus data traffic, etc. Generally, theQoS indicator may refer to any quality metric associated with thesidelink communications, e.g., a latency requirement, a reliabilityrequirement, etc. The service type indicator may identify the servicesto be carried in the sidelink communications (e.g., PSID or ITS-AID).

At 320, the UE may receive a configuration message from the base stationthat includes or otherwise conveys an indication of an identifier forthe sidelink communications using the second RAT. In some examples, theconfiguration message may be an RRC message that also includes orotherwise provides an indication of some available sidelink resources.In some aspects, the configuration message may include one or more bits,fields, flags, and the like, that are configured according to protocolsassociated with the second RAT.

At 325, the UE may transmit a request for resources to the base stationto use to perform the sidelink communications using the second RAT. Forexample, the resource request may include or otherwise convey anindication of the identifier signaled in the configuration message andone or more BSRs that are configured based on the resource request beingfor resources associated with the second RAT.

At 330, the UE may receive a grant for sidelink resources to use toperform the sidelink communications using the second RAT. In someaspects, the UE may receive a DCI in a control channel and descramblethe DCI using the identifier to recover the resource grant. In someexamples, the identifier is associated with two identifiers, e.g., afirst identifier and a second identifier, that are both associated withthe second RAT. For example, the two identifiers may be provided in asituation where different transmission types are being performed in thesidelink communications using the second RAT. For example, the basestation may transmit the grant in an enhanced PDCCH ((e)PDCCH) with aDCI scrambled with NR-v2X-RNTI and/or NR-V2X-URLLC-RNTI depending uponwhether resources are assigned for a first transmission type of thesecond RAT, a second transmission type of the second RAT, or both.Accordingly, the UE may use the first identifier to descramble the DCIto recover the resource grant for the first transmission type and usethe second identifier to descramble the DCI to recover the resourcegrant for the second transmission type.

In the situation where the UE is requesting sidelink resources for boththe second RAT and the first RAT, at 355 the UE may transmit a sidelinkinformation message to the base station using the first RAT, but thatprovides an indication that the sidelink communications are to beperformed using the second RAT and the first RAT. In some aspects, thesidelink information message may further include or otherwise provide anindication of a transmission type (e.g., indicating one or more ofnormal TTI, URLLC, MiCR, non-MiCR, etc., corresponding to a desiredlatency and type of resource allocation), a traffic profile, a qualityof service indicator, a service type indicator, and the like, for thesidelink communications using the second RAT and/or the first RAT.

At 340, the UE may receive a configuration message from the base stationthat includes or otherwise conveys an indication of an identifier forthe sidelink communications using the second RAT and the first RAT. Insome examples, the configuration message may be an RRC message that alsoincludes or otherwise provides an indication of some available sidelinkresources. In some aspects, the configuration message may include one ormore bits, fields, flags, and the like, that are configured according toprotocols associated with the first RAT and the second RAT.

At 345, the UE may transmit a request for resources to the base stationto use to perform the sidelink communications using the second RAT andthe first RAT. For example, the resource request may include orotherwise convey an indication of the identifier signaled in theconfiguration message and one or more BSRs that are configured based onthe resource request being for resources associated with the second RATand the first RAT.

At 350, the UE may receive a grant for sidelink resources to use toperform the sidelink communications using the second RAT and the firstRAT. In some aspects, the UE may receive a DCI in a control channel anddescramble the DCI using the identifier to recover the resource grant.In some examples, the identifier is associated with two identifiers,e.g., a first identifier and a second identifier, where each identifieris associated with a different RAT. Accordingly, the UE may use thefirst identifier to descramble the DCI to recover the resource grant forthe first RAT and use the second identifier to descramble the DCI torecover the resource grant for the second RAT. In some aspects, multipleidentifiers are provided in the RRC signaling, where some identifiersare associated with different RATs and other identifiers are associatedwith different transmission types.

Accordingly, and as applicable, at 355 the UE may perform the sidelinkcommunications using the granted resources. In the example where thesidelink communications use the second RAT, the UE may perform thesidelink communications with another UE using the second RAT using theallocated resources. In the example where the sidelink communicationsuse the first RAT and the second RAT, the UE may perform the sidelinkcommunications with one or more UEs using the first RAT and the secondRAT using the allocated resources, respectively.

FIG. 4 illustrates an example of protocol stack configurations 400 thatsupports multi-RAT scheduling of sidelink interface in accordance withaspects of the present disclosure. In some examples, protocol stackconfigurations 400 may be implemented by a base station 405, a UE 410,and a UE 415, which may be examples of the corresponding devicesdescribed herein.

Generally, protocol stack configurations 400 support base station 405providing scheduling grant for sidelink resources using multiple RATs.Base station 405 may include an RRC protocol layer 420, a PDCP/RLC layer425, a MAC layer 430, and a PHY layer 435. Generally, the protocol stackconfiguration of base station 205 may refer to a layered protocol stack.In the user plane, communications at the bearer or PDCP layer may beIP-based and the RLC layer may in some cases perform packet segmentationand reassembly to communicate over logical channels. MAC layer 430 mayperform priority handling and multiplexing of logical channels intotransport channels. MAC layer 430 may also use HARQ to provideretransmission at MAC layer 430 to improve link efficiency. In thecontrol plane, RRC protocol layer 420 may provide establishment,configuration, and maintenance of an RRC connection between a UE and abase station or core network supporting radio bearers for user planedata. At PHY layer 435, transport channels may be mapped to physicalchannels. Generally, the protocol stack configuration for a base station405 may support communications using a first RAT (e.g., an LTE RAT) anda second RAT (e.g., a NR RAT).

Generally, the protocol stack configuration for base station 405 mayprovide connectivity between base station 405 and an EPC, e.g., manageor otherwise provide communications over an S1 interface between basestation 405 and the EPC. Moreover, the protocol stack configuration forbase station 405 may also manage one or more aspects of supportingsidelink scheduling using a NR PC5 interface for UEs within the coveragearea of base station 405. For example, one or more layers of theprotocol stack configuration of base station 405 may indicate whetherthe nearby gNBs exists and/or whether base station 405 supports NR V2Xsidelink scheduling. The UEs within the coverage area may detect whetherbase station 405 supports NR PC5 scheduling, and, if not, can place theNR V2X operation in a non-use mode. Otherwise, the UE can use mode 3scheduling of sidelink resources. In other scenarios, the UE may detectthe existence of gNB that does not support NR V2X sidelink scheduling.

UE 410 may include an RRC protocol layer 440, a PDCP/RLC layer 445, aMAC layer 450, and a physical layer 455. Generally, each of these layersof UE 410 may perform similar functions as the corresponding layers ofbase station 405. For example, MAC layer 450 of UE 410 may communicateat the layer level with MAC layer 430 of base station 405 to performpriority handling and multiplexing of logical channels into transportchannels between the corresponding devices. As another example, RRCprotocol layer 440 of UE 410 may communicate at the layer level with RRCprotocol layer 420 of base station 405 to provide establishment,configuration, and maintenance of an RRC connection between UE 410 andbase station 405.

UE 410 may also be configured to support sidelink communications usingthe second RAT. Accordingly, UE 410 may also include an NR V2X layer460, and NR PDCP/RLC layer 465, a NR MAC layer 470, and a NR PHY layer475. Generally, each of these layers of UE 410 may perform, for thesecond RAT, functions similar to those the corresponding layers performfor the first RAT. For example, NR V2X layer 460 may provide forestablishment, configuration maintenance of an RRC connection between UE410 and UE 415 during sidelink communications. As another example, NRPHY layer 475 may map transport channels to physical channels accordingto the second RAT for UE 410.

Similarly, UE 415 may also be configured to support sidelinkcommunications using the second RAT. Accordingly, UE 415 may alsoinclude an NR V2X layer 480, a NR PDCP/RLC layer 485, a NR MAC layer490, and a NR physical layer 495. Each of these layers of UE 415 maycommunicate at the layer level with their corresponding layers of UE410. UE 415 may also optionally be equipped with protocol layerssupporting communications using the first RAT.

Accordingly, the protocol stack configurations for a base station 405,UE 410, and UE 415 may support aspects of the described techniques whereUE 410 determines that base station 405 supports allocating resourcesfor sidelink communications using a first RAT and a second RAT. Thelayers may support UE 410 transmitting a sidelink information message tobase station 405 using the first RAT that indicates that sidelinkcommunications are to be performed using either the second RAT or boththe first RAT and a second RAT. The layers may support UE 410 receivinga configuration message from base station 405 that comprises anidentifier for the sidelink communications and an indication ofavailable sidelink resources. The layers may support UE 410transmitting, based at least on some aspects on the configurationmessage, a request for resources within the available sidelink resourcesto base station 405. The request may include or otherwise provide anindication of the identifier and a BSR that is configured based onwhether the request for resources is for resources using the second RATor for resources using the first RAT and the second RAT.

FIG. 5 illustrates an example of a process 500 that supports multi-RATscheduling of sidelink interface in accordance with aspects of thepresent disclosure. In some examples, process 500 may implement aspectsof wireless communication systems 100/200, flowchart 300, and/orprotocol stack configurations 400. Process 500 may include a basestation 505, a UE 510, and a UE 515, which may be examples of thecorresponding devices described herein.

At 520, base station 505 may transmit (and UE 510 may receive) a messagethat indicates that base station 505 supports allocating resources forsidelink communications using a first RAT and a second RAT. Generally,the first RAT is different from the second RAT, e.g., the first RAT maybe an LTE RAT and the second RAT may be a NR RAT. The message may bebroadcast, such as in a SIB broadcast, a synchronization signal (SS)broadcast, and the like.

At 525, UE 510 may transmit (and base station 505 may receive) asidelink information message using the first RAT that indicates thatsidelink communications are to be performed using either the second RATor both the first RAT and the second RAT. In some aspects, the sidelinkinformation message may include additional information associated withthe sidelink communications, such as a transmission type (e.g.,indicating one or more of normal TTI, URLLC, MiCR, non-MiCR, etc.,corresponding to a desired latency and type of resource allocation), atraffic profile, a QoS indicator, a service type indicator, and thelike.

At 530, base station 505 may transmit (and UE 510 may receive) aconfiguration message that includes or otherwise provides an indicationof an identifier for the sidelink communications and/or an indication ofavailable sidelink resources. In some aspects, the identifier mayinclude more than one identifier, e.g., a first identifier and a secondidentifier, wherein each identifier is associated with a particular RAT,a particular transmission type, and the like. Examples of identifiersmay include, but are not limited to an LCID, a RNTI, and the like.

At 535, UE 510 may transmit (and base station 505 may receive) a requestfor resources within the available sidelink resources. In some aspectsthe resource request is based at least in part on the configurationmessage. In some aspects, the resource request may include other orotherwise provide an indication of the identifier and/or a BSR that isconfigured based at least in part on whether the resource request isassociated with the second RAT or both first RAT and the second RAT. Insome aspects, the resource request may include a first BSR associatedwith the first RAT and a second BSR associated with the second RAT. Insome aspects, the resource request may include a first BSR associatedwith a first transmission type using the second RAT and a second BSRassociated with a second transmission type that also uses the secondRAT. In some aspects, the BSR may include or otherwise provide anindication of a buffer status for the first RAT and a buffer status forthe second RAT. The buffer statuses indicated in the BSR may refer to anamount of data stored in the corresponding buffer, an indication of anamount of resources needed to transmit the data stored in thecorresponding buffer, and the like.

At 540, base station 505 may optionally transmit (and UE 510 mayoptionally receive) a resource grant allocating resources for UE 510 touse to perform the sidelink communications. In some aspects, this mayinclude base station 505 generating a resource grant that allocatesresources within the available sidelink resources and scrambling theresource grant using the identifier to generate a scrambled resourcegrant. Base station 505 may transmit a DCI in a control channel (e.g., aPDCCH) that includes or otherwise provides an indication of thescrambled resource grant. Accordingly, UE 510 may receive the DCI in thecontrol channel and use the identifier to descramble the DCI to obtainthe resource grant allocating the resources. In some aspects, theindication of the resource grant is not provided in a DCI scrambled withthe identifier but is included in the payload data in the control signal(e.g., indicated as explicit signaling in the PDCCH signal).

In some aspects where the identifier includes multiple identifiers, witheach identifier associated with a different RAT, this may include UE 510using the first identifier associated with the first RAT to descramblethe DCI to recover the resource grant allocating resources to the firstRAT and then using the second identifier associated with the second RATto descramble the DCI to recover resource grant allocating resources tothe second RAT.

In some aspects where the identifier includes multiple identifiers, witheach identifier associated with a different transmission type, this mayinclude UE 510 using the first identifier to descramble the DCI todetermine whether the DCI includes a resource grant allocating resourcesto the second RAT associated with a first transmission type (e.g.,normal TTI) and then using a second identifier to descramble the DCI todetermine whether the DCI includes a resource grant allocating resourcesto the second RAT associated with a second transmission type (e.g.,URLLC).

At 545, UE 510 may optionally use the allocated resources to perform thesidelink communications with UE 515. In the example where the resourcesare allocated for sidelink communications using the first RAT and thesecond RAT, UE 510 may to perform the sidelink communications with UE515 using the resources allocated for both the first RAT and the secondRAT, or may perform sidelink communications with UE 515 using theresources allocated for the first RAT and then using the resourcesallocated for the second RAT to perform sidelink communications with adifferent UE.

FIG. 6 shows a block diagram 600 of a UE 605 that supports multi-RATscheduling of sidelink interface in accordance with aspects of thepresent disclosure. UE 605 may be an example of aspects of a UE 115 asdescribed herein. UE 605 may include a receiver 610, a communicationsmanager 615, and a transmitter 620. UE 605 may also include a processor.Each of these components may be in communication with one another (e.g.,via one or more buses).

Receiver 610 may receive information such as packets, user data, orcontrol information associated with various information channels (e.g.,control channels, data channels, and information related to multi-RATscheduling of sidelink interface, etc.). Information may be passed on toother components of the device. Receiver 610 may be an example ofaspects of a transceiver 920 described with reference to FIG. 9 .Receiver 610 may utilize a single antenna or a set of antennas.

Communications manager 615 may receive a message indicating that a basestation supports allocating resources for sidelink communications usinga first RAT and a second RAT that is different from the first RAT.Communications manager 615 may transmit a sidelink information messageto the base station using the first RAT that indicates that sidelinkcommunications are to be performed using either the second RAT or boththe first RAT and the second RAT. Communications manager 615 may receivea configuration message from the base station that includes anidentifier for the sidelink communications and an indication ofavailable sidelink resources. Communications manager 615 may transmit,based on the configuration message, a request for resources within theavailable sidelink resources, the request indicating the identifier anda BSR configured based on whether the request for resources isassociated with the second RAT or both the first RAT and the second RAT.Communications manager 615 may be an example of aspects of thecommunications manager 910 described with reference to FIG. 9 .

Communications manager 615 or its sub-components, may be implemented inhardware, code (e.g., software or firmware) executed by a processor, orany combination thereof. If implemented in code executed by a processor,the functions of the communications manager 615 and/or at least some ofits various sub-components may be executed by a general-purposeprocessor, a digital signal processor (DSP), an application-specificintegrated circuit (ASIC), a field-programmable gate array (FPGA) orother programmable logic device, discrete gate or transistor logic,discrete hardware components, or any combination thereof designed toperform the functions described in the present disclosure.

Communications manager 615 or its sub-components, may be physicallylocated at various positions, including being distributed such thatportions of functions are implemented at different physical locations byone or more physical devices. In some examples, communications manager615 or its sub-components may be a separate and distinct component inaccordance with various aspects of the present disclosure. In someexamples, communications manager 615 or its sub-components may becombined with one or more other hardware components, including but notlimited to an input/output (I/O) component, a transceiver, a networkserver, another computing device, one or more other components describedin the present disclosure, or a combination thereof in accordance withvarious aspects of the present disclosure.

Transmitter 620 may transmit signals generated by other components of UE605. In some examples, transmitter 620 may be collocated with a receiver610 in a transceiver module. For example, transmitter 620 may be anexample of aspects of transceiver 920 described with reference to FIG. 9. Transmitter 620 may utilize a single antenna or a set of antennas.

FIG. 7 shows a block diagram 700 of a device 705 that supports multi-RATscheduling of sidelink interface in accordance with aspects of thepresent disclosure. Device 705 may be an example of aspects of a UE 605or a UE 115 as described with reference to FIGS. 1 and 6 . Device 705may include a receiver 710, a communications manager 715, and atransmitter 740. Device 705 may also include a processor. Each of thesecomponents may be in communication with one another (e.g., via one ormore buses).

Receiver 710 may receive information such as packets, user data, orcontrol information associated with various information channels (e.g.,control channels, data channels, and information related to multi-RATscheduling of sidelink interface, etc.). Information may be passed on toother components of the device. Receiver 710 may be an example ofaspects of transceiver 920 described with reference to FIG. 9 . Receiver710 may utilize a single antenna or a set of antennas.

Communications manager 715 may also include a multi-RAT support manager720, a sidelink information message manager 725, a configuration messagemanager 730, and a resource request manager 735. Communications manager715 may be an example of aspects of communications manager 910 describedwith reference to FIG. 9 .

Multi-RAT support manager 720 may receive a message indicating that abase station supports allocating resources for sidelink communicationsusing a first RAT and a second RAT that is different from the first RAT.

Sidelink information message manager 725 may transmit a sidelinkinformation message to the base station using the first RAT thatindicates that sidelink communications are to be performed using eitherthe second RAT or both the first RAT and the second RAT.

Configuration message manager 730 may receive a configuration messagefrom the base station that includes an identifier for the sidelinkcommunications and an indication of available sidelink resources.

Resource request manager 735 may transmit, based on the configurationmessage, a request for resources within the available sidelinkresources, the request indicating the identifier and a BSR configuredbased on whether the request for resources is associated with the secondRAT or both the first RAT and the second RAT.

Transmitter 740 may transmit signals generated by other components ofdevice 705. In some examples, the transmitter 740 may be collocated witha receiver 710 in a transceiver module. For example, the transmitter 740may be an example of aspects of the transceiver 920 described withreference to FIG. 9 . The transmitter 740 may utilize a single antennaor a set of antennas.

FIG. 8 shows a block diagram 800 of a communications manager 805 thatsupports multi-RAT scheduling of sidelink interface in accordance withaspects of the present disclosure. Communications manager 815 may be anexample of aspects of a communications manager 615, a communicationsmanager 715, or a communications manager 910 described with reference toFIGS. 6, 7, and 9 . Communications manager 815 may include a multi-RATsupport manager 810, a sidelink information message manager 815, aconfiguration message manager 820, a resource request manager 825, aresource grant manager 830, a dual-RAT identifier manager 835, a dual-TTidentifier manager 840, and a dual-transmission type manager 845. Eachof these modules may communicate, directly or indirectly, with oneanother (e.g., via one or more buses).

Multi-RAT support manager 810 may receive a message indicating that abase station supports allocating resources for sidelink communicationsusing a first RAT and a second RAT that is different from the first RAT.In some cases, the message is a SIB message that is broadcast by thebase station. In some cases, the first RAT is an LTE RAT and the secondRAT is an NR RAT.

Sidelink information message manager 815 may transmit a sidelinkinformation message to the base station using the first RAT thatindicates that sidelink communications are to be performed using eitherthe second RAT or both the first RAT and the second RAT. In some cases,the sidelink information message indicates a transmission type (e.g.,indicating one or more of normal TTI, URLLC, MiCR, non-MiCR, etc.,corresponding to a desired latency and type of resource allocation), atraffic profile, a quality of service indicator, a service typeindicator, or any combination thereof, for the sidelink communications.

Configuration message manager 820 may receive a configuration messagefrom the base station that includes an identifier for the sidelinkcommunications and an indication of available sidelink resources. Insome cases, the configuration message indicates a mapping assignment fora logical channel associated with the first RAT or the second RAT. Insome cases, the identifier is at least one of a LCID or a RNTI. In somecases, the configuration message is an RRC message.

Resource request manager 825 may transmit, based on the configurationmessage, a request for resources within the available sidelinkresources, the request indicating the identifier and a BSR configuredbased on whether the request for resources is associated with the secondRAT or both the first RAT and the second RAT. In some cases, the BSRindicates a buffer status for the first RAT and a buffer status for thesecond RAT.

Resource grant manager 830 may receive DCI in a control channel. In someexamples, resource grant manager 830 may descramble the DCI using theidentifier to obtain a resource grant allocating resources within theavailable sidelink resources. In some examples, resource grant manager830 may perform the sidelink communications using the allocatedresources.

Dual-RAT identifier manager 835 may receive DCI in a control channel. Insome examples, dual-RAT identifier manager 835 may descramble the DCIusing the first identifier for determining whether the DCI includes aresource grant allocating resources to the first RAT. In some examples,dual-RAT identifier manager 835 may descramble the DCI using the secondidentifier for determining whether the DCI includes a resource grantallocating resources to the second RAT. In some cases, the identifierincludes a first identifier associated with the first RAT and a secondidentifier associated with the second RAT.

Dual-TT identifier manager 840 may monitor, control, or otherwise manageone or more aspects of the identifier including a first identifierassociated with the second RAT and a second identifier associated withthe second RAT.

Dual-transmission type manager 845 may receive DCI in a control channel.In some examples, dual-transmission type manager 845 may descramble theDCI using the first identifier for determining whether the DCI includesa resource grant allocating resources to the second RAT associated witha first transmission type. In some examples, dual-transmission typemanager 845 may descramble the DCI using the second identifier fordetermining whether the DCI includes a resource grant allocatingresources to the second RAT associated with a second transmission type.

FIG. 9 shows a diagram of a system 900 including a device 905 thatsupports multi-RAT scheduling of sidelink interface in accordance withaspects of the present disclosure. Device 905 may be an example of orinclude the components of UE 605, UE 705, or a UE 115 as describedabove, e.g., with reference to FIGS. 6 and 7 . Device 905 may includecomponents for bi-directional voice and data communications includingcomponents for transmitting and receiving communications, including acommunications manager 910, a I/O controller 915, a transceiver 920, anantenna 925, a memory 930, a processor 940, and a software 935. Thesecomponents may be in electronic communication via one or more buses(e.g., bus 945).

I/O controller 915 may manage input and output signals for device 905.I/O controller 915 may also manage peripherals not integrated intodevice 905. In some cases, I/O controller 915 may represent a physicalconnection or port to an external peripheral. In some cases, I/Ocontroller 915 may utilize an operating system such as iOS®, ANDROID®,MS-DOS®, MS-WINDOWS®, OS/2®, UNIX®, LINUX®, or another known operatingsystem. In other cases, I/O controller 915 may represent or interactwith a modem, a keyboard, a mouse, a touchscreen, or a similar device.In some cases, I/O controller 915 may be implemented as part of aprocessor. In some cases, a user may interact with device 905 via I/Ocontroller 915 or via hardware components controlled by I/O controller915.

Transceiver 920 may communicate bi-directionally, via one or moreantennas, wired, or wireless links as described above. For example,transceiver 920 may represent a wireless transceiver and may communicatebi-directionally with another wireless transceiver. Transceiver 920 mayalso include a modem to modulate the packets and provide the modulatedpackets to the antennas for transmission, and to demodulate packetsreceived from the antennas.

In some cases, device 905 may include a single antenna 925. However, insome cases device 905 may have more than one antenna 925, which may becapable of concurrently transmitting or receiving multiple wirelesstransmissions.

Memory 930 may include RAM and ROM. Memory 930 may storecomputer-readable, computer-executable code 935 including instructionsthat, when executed, cause the processor to perform various functionsdescribed herein. In some cases, memory 930 may contain, among otherthings, a BIOS which may control basic hardware or software operationsuch as the interaction with peripheral components or devices.

Processor 940 may include an intelligent hardware device, (e.g., ageneral-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, anFPGA, a programmable logic device, a discrete gate or transistor logiccomponent, a discrete hardware component, or any combination thereof).In some cases, processor 940 may be configured to operate a memory arrayusing a memory controller. In other cases, a memory controller may beintegrated into processor 940. Processor 940 may be configured toexecute computer-readable instructions stored in a memory to performvarious functions (e.g., functions or tasks supporting multi-RATscheduling of sidelink interface).

Code 935 may include code to implement aspects of the presentdisclosure, including code to support wireless communications. Code 935may be stored in a non-transitory computer-readable medium such assystem memory or other memory. In some cases, code 935 may not bedirectly executable by the processor but may cause a computer (e.g.,when compiled and executed) to perform functions described herein.

FIG. 10 shows a block diagram 1000 of a base station 1005 that supportsmulti-RAT scheduling of sidelink interface in accordance with aspects ofthe present disclosure. Base station 1005 may be an example of aspectsof a base station 105 as described herein. Base station 1005 may includea receiver 1010, a communications manager 1015, and a transmitter 1020.Base station 1005 may also include a processor. Each of these componentsmay be in communication with one another (e.g., via one or more buses).

Receiver 1010 may receive information such as packets, user data, orcontrol information associated with various information channels (e.g.,control channels, data channels, and information related to multi-RATscheduling of sidelink interface, etc.). Information may be passed on toother components of base station 1005. Receiver 1010 may be an exampleof aspects of a transceiver 1320 described with reference to FIG. 13 .Receiver 1010 may utilize a single antenna or a set of antennas.

Communications manager 1015 may receive a sidelink information messagefrom a UE using a first RAT indicating that sidelink communications areto be performed using a second RAT or both the first RAT and the secondRAT. Communications manager 1015 may transmit a configuration message tothe UE that includes an identifier for the sidelink communications andan indication of available sidelink resources. Communications manager1015 may receive, based on the configuration message, a request forresources within the available sidelink resources, the requestindicating the identifier and a BSR configured based on whether therequest for resources is associated with the second RAT or both thefirst RAT and the second RAT. Communications manager 1015 may be anexample of aspects of communications manager 1310 described withreference to FIG. 13 .

Communications manager 1015 or its sub-components, may be implemented inhardware, code (e.g., software or firmware) executed by a processor, orany combination thereof. If implemented in code executed by a processor,the functions of communications manager 1015 and/or at least some of itsvarious sub-components may be executed by a general-purpose processor, aDSP, an ASIC, an FPGA or other programmable logic device, discrete gateor transistor logic, discrete hardware components, or any combinationthereof designed to perform the functions described in the presentdisclosure.

Communications manager 1015 or its sub-components, may be physicallylocated at various positions, including being distributed such thatportions of functions are implemented at different physical locations byone or more physical devices. In some examples, communications manager1015 or its sub-components may be a separate and distinct component inaccordance with various aspects of the present disclosure. In someexamples, communications manager 1015 or its sub-components may becombined with one or more other hardware components, including but notlimited to an input/output (I/O) component, a transceiver, a networkserver, another computing device, one or more other components describedin the present disclosure, or a combination thereof in accordance withvarious aspects of the present disclosure.

Transmitter 1020 may transmit signals generated by other components ofthe device. In some examples, transmitter 1020 may be collocated with areceiver 1010 in a transceiver module. For example, transmitter 1020 maybe an example of aspects of transceiver 1320 described with reference toFIG. 13 . Transmitter 1020 may utilize a single antenna or a set ofantennas.

FIG. 11 shows a block diagram 1100 of a device 1105 that supportsmulti-RAT scheduling of sidelink interface in accordance with aspects ofthe present disclosure. Device 1105 may be an example of aspects of abase station 1005 or a base station 105 as described with reference toFIGS. 1 and 10 . Device 1105 may include a receiver 1110, acommunications manager 1115, and a transmitter 1135. Device 1105 mayalso include a processor. Each of these components may be incommunication with one another (e.g., via one or more buses).

Receiver 1110 may receive information such as packets, user data, orcontrol information associated with various information channels (e.g.,control channels, data channels, and information related to multi-RATscheduling of sidelink interface, etc.). Information may be passed on toother components of the device. Receiver 1110 may be an example ofaspects of transceiver 1320 described with reference to FIG. 13 .Receiver 1110 may utilize a single antenna or a set of antennas.

Communications manager 1115 may also include a sidelink informationmessage manager 1120, a configuration message manager 1125, and aresource request manager 1130. Communications manager 1115 may be anexample of aspects of communications manager 1310 described withreference to FIG. 13 .

Sidelink information message manager 1120 may receive a sidelinkinformation message from a UE using a first RAT indicating that sidelinkcommunications are to be performed using a second RAT or both the firstRAT and the second RAT.

Configuration message manager 1125 may transmit a configuration messageto the UE that includes an identifier for the sidelink communicationsand an indication of available sidelink resources.

Resource request manager 1130 may receive, based on the configurationmessage, a request for resources within the available sidelinkresources, the request indicating the identifier and a BSR configuredbased on whether the request for resources is associated with the secondRAT or both the first RAT and the second RAT.

Transmitter 1135 may transmit signals generated by other components ofthe device. In some examples, transmitter 1135 may be collocated with areceiver 1110 in a transceiver module. For example, transmitter 1135 maybe an example of aspects of transceiver 1320 described with reference toFIG. 13 . Transmitter 1135 may utilize a single antenna or a set ofantennas.

FIG. 12 shows a block diagram 1200 of a communications manager 1205 thatsupports multi-RAT scheduling of sidelink interface in accordance withaspects of the present disclosure. Communications manager 1215 may be anexample of aspects of a communications manager 1015, a communicationsmanager 1115, or a communications manager 1310 described with referenceto FIGS. 10, 11, and 13 . Communications manager 1215 may include asidelink information message manager 1210, a configuration messagemanager 1215, a resource request manager 1220, a resource grant manager1225, a dual-RAT identifier manager 1230, a dual-transmission typemanager 1235, and a multi-RAT support manager 1240. Each of thesemodules may communicate, directly or indirectly, with one another (e.g.,via one or more buses).

Sidelink information message manager 1210 may receive a sidelinkinformation message from a UE using a first RAT indicating that sidelinkcommunications are to be performed using a second RAT or both the firstRAT and the second RAT. In some cases, the sidelink information messageidentifies a transmission type (e.g., indicating one or more of normalTTI, URLLC, MiCR, non-MiCR, etc., corresponding to a desired latency andtype of resource allocation), a traffic profile, a quality of serviceindicator, a service type indicator, or any combination thereof, for thesidelink communications.

Configuration message manager 1215 may transmit a configuration messageto the UE that includes an identifier for the sidelink communicationsand an indication of available sidelink resources. In some cases, theidentifier is at least one of a LCID or a RNTI. In some cases, theconfiguration message is an RRC message.

Resource request manager 1220 may receive, based on the configurationmessage, a request for resources within the available sidelinkresources, the request indicating the identifier and a BSR configuredbased on whether the request for resources is associated with the secondRAT or both the first RAT and the second RAT. In some cases, the BSRindicates a buffer status for the first RAT and a buffer status for thesecond RAT.

Resource grant manager 1225 may generate a resource grant allocatingresources within the available sidelink resources to perform thesidelink communications. In some examples, resource grant manager 1225may scramble the resource grant using the identifier to generate ascrambled resource grant. In some examples, transmitting, in a controlchannel, DCI that includes the scrambled resource grant.

Dual-RAT identifier manager 1230 may generate a first resource grantallocating first resources within the available sidelink resources tothe first RAT and a second resource grant allocating second resourceswithin the available sidelink resources to the second RAT. In someexamples, dual-RAT identifier manager 1230 may scramble the firstresource grant using the first identifier to generate a first scrambledresource grant. In some examples, dual-RAT identifier manager 1230 mayscramble the second resource grant using the second identifier togenerate a second scrambled resource grant. In some examples,transmitting, in a control channel, DCI that includes the firstscrambled resource grant and the second scrambled resource grant. Insome cases, the identifier includes a first identifier associated withthe first RAT and a second identifier associated with the second RAT.

Dual-transmission type manager 1235 may generate a first resource grantallocating first resources within the available sidelink resources tothe second RAT and a second resource grant allocating second resourceswithin the available sidelink resources to the second RAT. In someexamples, dual-transmission type manager 1235 may scramble the firstresource grant using the first identifier to generate a first scrambledresource grant. In some examples, dual-transmission type manager 1235may scramble the second resource grant using the second identifier togenerate a second scrambled resource grant. In some examples,transmitting, in a control channel, DCI that includes the firstscrambled resource grant and the second scrambled resource grant. Insome cases, the identifier includes a first identifier associated withthe second RAT and a second identifier associated with the second RAT.

Multi-RAT support manager 1240 may transmit a SIB message indicatingsupport for allocating resources for sidelink communications using thefirst RAT and the second RAT. In some cases, the first RAT is an LTE RATand the second RAT is an NR RAT.

FIG. 13 shows a diagram of a system 1300 including a device 1305 thatsupports multi-RAT scheduling of sidelink interface in accordance withaspects of the present disclosure. Device 1305 may be an example of orinclude the components of base station 1005, base station 1105, or abase station 105 as described above, e.g., with reference to FIGS. 10and 11 . Device 1305 may include components for bi-directional voice anddata communications including components for transmitting and receivingcommunications, including a communications manager 1310, a networkcommunications manager 1315, a transceiver 1320, an antenna 1325, amemory 1330, a processor 1340, an inter-station communications manager1345, and a software 1335. These components may be in electroniccommunication via one or more buses (e.g., bus 1350).

Network communications manager 1315 may manage communications with thecore network (e.g., via one or more wired backhaul links). For example,network communications manager 1315 may manage the transfer of datacommunications for client devices, such as one or more UEs 115.

Transceiver 1320 may communicate bi-directionally, via one or moreantennas, wired, or wireless links as described above. For example,transceiver 1320 may represent a wireless transceiver and maycommunicate bi-directionally with another wireless transceiver.Transceiver 1320 may also include a modem to modulate the packets andprovide the modulated packets to the antennas for transmission, and todemodulate packets received from the antennas.

In some cases, device 1305 may include a single antenna 1325. However,in some cases device 1305 may have more than one antenna 1325, which maybe capable of concurrently transmitting or receiving multiple wirelesstransmissions.

Memory 1330 may include RAM and ROM. Memory 1330 may storecomputer-readable, computer-executable code 1335 including instructionsthat, when executed, cause the processor to perform various functionsdescribed herein. In some cases, memory 1330 may contain, among otherthings, a BIOS which may control basic hardware or software operationsuch as the interaction with peripheral components or devices.

Processor 1340 may include an intelligent hardware device (e.g., ageneral-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, anFPGA, a programmable logic device, a discrete gate or transistor logiccomponent, a discrete hardware component, or any combination thereof).In some cases, processor 1340 may be configured to operate a memoryarray using a memory controller. In other cases, a memory controller maybe integrated into processor 1340. Processor 1340 may be configured toexecute computer-readable instructions stored in a memory to performvarious functions (e.g., functions or tasks supporting multi-RATscheduling of sidelink interface).

Inter-station communications manager 1345 may manage communications withother base station 105 and may include a controller or scheduler forcontrolling communications with UEs 115 in cooperation with other basestations 105. For example, inter-station communications manager 1345 maycoordinate scheduling for transmissions to UEs 115 for variousinterference mitigation techniques such as beamforming or jointtransmission. In some examples, inter-station communications manager1345 may provide an X2 interface within an LTE/LTE-A wirelesscommunication network technology to provide communication between basestations 105.

Code 1335 may include code to implement aspects of the presentdisclosure, including code to support wireless communications. Code 1335may be stored in a non-transitory computer-readable medium such assystem memory or other memory. In some cases, code 1335 may not bedirectly executable by the processor but may cause a computer (e.g.,when compiled and executed) to perform functions described herein.

FIG. 14 shows a flowchart illustrating a method 1400 for multi-RATscheduling of sidelink interface in accordance with aspects of thepresent disclosure. The operations of method 1400 may be implemented bya UE or its components as described herein. For example, the operationsof method 1400 may be performed by a communications manager as describedwith reference to FIGS. 6 to 9 . In some examples, a UE may execute aset of instructions to control the functional elements of the UE toperform the functions described below. Additionally, or alternatively, aUE may perform aspects of the functions described below usingspecial-purpose hardware.

At 1405, the UE may receive a message indicating that a base stationsupports allocating resources for sidelink communications using a firstRAT and a second RAT that is different from the first RAT. Theoperations of 1405 may be performed according to the methods describedherein. In some examples, aspects of the operations of 1405 may beperformed by a multi-RAT support manager as described with reference toFIGS. 6 to 9 .

At 1410, the UE may transmit a sidelink information message to the basestation using the first RAT that indicates that sidelink communicationsare to be performed using either the second RAT or both the first RATand the second RAT. The operations of 1410 may be performed according tothe methods described herein. In some examples, aspects of theoperations of 1410 may be performed by a sidelink information messagemanager as described with reference to FIGS. 6 to 9 .

At 1415, the UE may receive a configuration message from the basestation that comprises an identifier for the sidelink communications andan indication of available sidelink resources. The operations of 1415may be performed according to the methods described herein. In someexamples, aspects of the operations of 1415 may be performed by aconfiguration message manager as described with reference to FIGS. 6 to9 .

At 1420, the UE may transmit, based at least in part on theconfiguration message, a request for resources within the availablesidelink resources, the request indicating the identifier and a BSRconfigured based at least in part on whether the request for resourcesis associated with the second RAT or both the first RAT and the secondRAT. The operations of 1420 may be performed according to the methodsdescribed herein. In some examples, aspects of the operations of 1420may be performed by a resource request manager as described withreference to FIGS. 6 to 9 .

FIG. 15 shows a flowchart illustrating a method 1500 for multi-RATscheduling of sidelink interface in accordance with aspects of thepresent disclosure. The operations of method 1500 may be implemented bya UE or its components as described herein. For example, the operationsof method 1500 may be performed by a communications manager as describedwith reference to FIGS. 6 to 9 . In some examples, a UE may execute aset of instructions to control the functional elements of the UE toperform the functions described below. Additionally, or alternatively, aUE may perform aspects of the functions described below usingspecial-purpose hardware.

At 1505, the UE may receive a message indicating that a base stationsupports allocating resources for sidelink communications using a firstRAT and a second RAT that is different from the first RAT. Theoperations of 1505 may be performed according to the methods describedherein. In some examples, aspects of the operations of 1505 may beperformed by a multi-RAT support manager as described with reference toFIGS. 6 to 9 .

At 1510, the UE may transmit a sidelink information message to the basestation using the first RAT that indicates that sidelink communicationsare to be performed using either the second RAT or both the first RATand the second RAT. The operations of 1510 may be performed according tothe methods described herein. In some examples, aspects of theoperations of 1510 may be performed by a sidelink information messagemanager as described with reference to FIGS. 6 to 9 .

At 1515, the UE may receive a configuration message from the basestation that comprises an identifier for the sidelink communications andan indication of available sidelink resources. The operations of 1515may be performed according to the methods described herein. In someexamples, aspects of the operations of 1515 may be performed by aconfiguration message manager as described with reference to FIGS. 6 to9 .

At 1520, the UE may transmit, based at least in part on theconfiguration message, a request for resources within the availablesidelink resources, the request indicating the identifier and a BSRconfigured based at least in part on whether the request for resourcesis associated with the second RAT or both the first RAT and the secondRAT. The operations of 1520 may be performed according to the methodsdescribed herein. In some examples, aspects of the operations of 1520may be performed by a resource request manager as described withreference to FIGS. 6 to 9 .

At 1525, the UE may receive DCI in a control channel. The operations of1525 may be performed according to the methods described herein. In someexamples, aspects of the operations of 1525 may be performed by aresource grant manager as described with reference to FIGS. 6 to 9 .

At 1530, the UE may descramble the DCI using the identifier to obtain aresource grant allocating resources within the available sidelinkresources. The operations of 1530 may be performed according to themethods described herein. In some examples, aspects of the operations of1530 may be performed by a resource grant manager as described withreference to FIGS. 6 to 9 .

At 1535, the UE may perform the sidelink communications using theallocated resources. The operations of 1535 may be performed accordingto the methods described herein. In some examples, aspects of theoperations of 1535 may be performed by a resource grant manager asdescribed with reference to FIGS. 6 to 9 .

FIG. 16 shows a flowchart illustrating a method 1600 for multi-RATscheduling of sidelink interface in accordance with aspects of thepresent disclosure. The operations of method 1600 may be implemented bya base station or its components as described herein. For example, theoperations of method 1600 may be performed by a communications manageras described with reference to FIGS. 10 to 13 . In some examples, a basestation may execute a set of instructions to control the functionalelements of the base station to perform the functions described below.Additionally, or alternatively, a base station may perform aspects ofthe functions described below using special-purpose hardware.

At 1605, the base station may receive a sidelink information messagefrom a UE using a first RAT indicating that sidelink communications areto be performed using a second RAT or both the first RAT and the secondRAT. The operations of 1605 may be performed according to the methodsdescribed herein. In some examples, aspects of the operations of 1605may be performed by a sidelink information message manager as describedwith reference to FIGS. 10 to 13 .

At 1610, the base station may transmit a configuration message to the UEthat comprises an identifier for the sidelink communications and anindication of available sidelink resources. The operations of 1610 maybe performed according to the methods described herein. In someexamples, aspects of the operations of 1610 may be performed by aconfiguration message manager as described with reference to FIGS. 10 to13 .

At 1615, the base station may receive, based at least in part on theconfiguration message, a request for resources within the availablesidelink resources, the request indicating the identifier and a BSRconfigured based at least in part on whether the request for resourcesis associated with the second RAT or both the first RAT and the secondRAT. The operations of 1615 may be performed according to the methodsdescribed herein. In some examples, aspects of the operations of 1615may be performed by a resource request manager as described withreference to FIGS. 10 to 13 .

FIG. 17 shows a flowchart illustrating a method 1700 for multi-RATscheduling of sidelink interface in accordance with aspects of thepresent disclosure. The operations of method 1700 may be implemented bya base station or its components as described herein. For example, theoperations of method 1700 may be performed by a communications manageras described with reference to FIGS. 10 to 13 . In some examples, a basestation may execute a set of instructions to control the functionalelements of the base station to perform the functions described below.Additionally, or alternatively, a base station may perform aspects ofthe functions described below using special-purpose hardware.

At 1705 the base station may transmit a SIB message indicating supportfor allocating resources for sidelink communications using the first RATand the second RAT. The operations of 1705 may be performed according tothe methods described herein. In some examples, aspects of theoperations of 1705 may be performed by a multi-RAT support manager asdescribed with reference to FIGS. 10 to 13 .

At 1710, the base station may receive a sidelink information messagefrom a UE using a first RAT indicating that sidelink communications areto be performed using a second RAT or both the first RAT and the secondRAT. The operations of 1710 may be performed according to the methodsdescribed herein. In some examples, aspects of the operations of 1710may be performed by a sidelink information message manager as describedwith reference to FIGS. 10 to 13 .

At 1715, the base station may transmit a configuration message to the UEthat comprises an identifier for the sidelink communications and anindication of available sidelink resources. The operations of 1715 maybe performed according to the methods described herein. In someexamples, aspects of the operations of 1715 may be performed by aconfiguration message manager as described with reference to FIGS. 10 to13 .

At 1720, the base station may receive, based at least in part on theconfiguration message, a request for resources within the availablesidelink resources, the request indicating the identifier and a BSRconfigured based at least in part on whether the request for resourcesis associated with the second RAT or both the first RAT and the secondRAT. The operations of 1720 may be performed according to the methodsdescribed herein. In some examples, aspects of the operations of 1720may be performed by a resource request manager as described withreference to FIGS. 10 to 13 .

It should be noted that the methods described above describe possibleimplementations, and that the operations and the steps may be rearrangedor otherwise modified and that other implementations are possible.Further, aspects from two or more of the methods may be combined.

Techniques described herein may be used for various wirelesscommunications systems such as code division multiple access (CDMA),time division multiple access (TDMA), frequency division multiple access(FDMA), orthogonal frequency division multiple access (OFDMA), singlecarrier frequency division multiple access (SC-FDMA), and other systems.A CDMA system may implement a radio technology such as CDMA2000,Universal Terrestrial Radio Access (UTRA), etc. CDMA2000 covers IS-2000,IS-95, and IS-856 standards. IS-2000 Releases may be commonly referredto as CDMA2000 1×, 1×, etc. IS-856 (TIA-856) is commonly referred to asCDMA2000 1×EV-DO, High Rate Packet Data (HRPD), etc. UTRA includesWideband CDMA (WCDMA) and other variants of CDMA. A TDMA system mayimplement a radio technology such as Global System for MobileCommunications (GSM).

An OFDMA system may implement a radio technology such as Ultra MobileBroadband (UMB), Evolved UTRA (E-UTRA), Institute of Electrical andElectronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE802.20, Flash-OFDM, etc. UTRA and E-UTRA are part of Universal MobileTelecommunications System (UMTS). LTE, LTE-A, and LTE-A Pro are releasesof UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, LTE-A Pro, NR,and GSM are described in documents from the organization named “3rdGeneration Partnership Project” (3GPP). CDMA2000 and UMB are describedin documents from an organization named “3rd Generation PartnershipProject 2” (3GPP2). The techniques described herein may be used for thesystems and radio technologies mentioned above as well as other systemsand radio technologies. While aspects of an LTE, LTE-A, LTE-A Pro, or NRsystem may be described for purposes of example, and LTE, LTE-A, LTE-APro, or NR terminology may be used in much of the description, thetechniques described herein are applicable beyond LTE, LTE-A, LTE-A Pro,or NR applications.

A macro cell generally covers a relatively large geographic area (e.g.,several kilometers in radius) and may allow unrestricted access by UEs115 with service subscriptions with the network provider. A small cellmay be associated with a lower-powered base station 105, as comparedwith a macro cell, and a small cell may operate in the same or different(e.g., licensed, unlicensed, etc.) frequency bands as macro cells. Smallcells may include pico cells, femto cells, and micro cells according tovarious examples. A pico cell, for example, may cover a small geographicarea and may allow unrestricted access by UEs 115 with servicesubscriptions with the network provider. A femto cell may also cover asmall geographic area (e.g., a home) and may provide restricted accessby UEs 115 having an association with the femto cell (e.g., UEs 115 in aclosed subscriber group (CSG), UEs 115 for users in the home, and thelike). An eNB for a macro cell may be referred to as a macro eNB. An eNBfor a small cell may be referred to as a small cell eNB, a pico eNB, afemto eNB, or a home eNB. An eNB may support one or multiple (e.g., two,three, four, and the like) cells, and may also support communicationsusing one or multiple component carriers.

The wireless communications system 100 or systems described herein maysupport synchronous or asynchronous operation. For synchronousoperation, the base stations 105 may have similar frame timing, andtransmissions from different base stations 105 may be approximatelyaligned in time. For asynchronous operation, the base stations 105 mayhave different frame timing, and transmissions from different basestations 105 may not be aligned in time. The techniques described hereinmay be used for either synchronous or asynchronous operations.

Information and signals described herein may be represented using any ofa variety of different technologies and techniques. For example, data,instructions, commands, information, signals, bits, symbols, and chipsthat may be referenced throughout the above description may berepresented by voltages, currents, electromagnetic waves, magneticfields or particles, optical fields or particles, or any combinationthereof.

The various illustrative blocks and modules described in connection withthe disclosure herein may be implemented or performed with ageneral-purpose processor, a DSP, an ASIC, an FPGA or other programmablelogic device (PLD), discrete gate or transistor logic, discrete hardwarecomponents, or any combination thereof designed to perform the functionsdescribed herein. A general-purpose processor may be a microprocessor,but in the alternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices (e.g., a combinationof a DSP and a microprocessor, multiple microprocessors, one or moremicroprocessors in conjunction with a DSP core, or any other suchconfiguration).

The functions described herein may be implemented in hardware, softwareexecuted by a processor, firmware, or any combination thereof. Ifimplemented in software executed by a processor, the functions may bestored on or transmitted over as one or more instructions or code on acomputer-readable medium. Other examples and implementations are withinthe scope of the disclosure and appended claims. For example, due to thenature of software, functions described above can be implemented usingsoftware executed by a processor, hardware, firmware, hardwiring, orcombinations of any of these. Features implementing functions may alsobe physically located at various positions, including being distributedsuch that portions of functions are implemented at different physicallocations.

Computer-readable media includes both non-transitory computer storagemedia and communication media including any medium that facilitatestransfer of a computer program from one place to another. Anon-transitory storage medium may be any available medium that can beaccessed by a general purpose or special purpose computer. By way ofexample, and not limitation, non-transitory computer-readable media mayinclude random-access memory (RAM), read-only memory (ROM), electricallyerasable programmable read only memory (EEPROM), flash memory, compactdisk (CD) ROM or other optical disk storage, magnetic disk storage orother magnetic storage devices, or any other non-transitory medium thatcan be used to carry or store desired program code means in the form ofinstructions or data structures and that can be accessed by ageneral-purpose or special-purpose computer, or a general-purpose orspecial-purpose processor. Also, any connection is properly termed acomputer-readable medium. For example, if the software is transmittedfrom a website, server, or other remote source using a coaxial cable,fiber optic cable, twisted pair, digital subscriber line (DSL), orwireless technologies such as infrared, radio, and microwave, then thecoaxial cable, fiber optic cable, twisted pair, DSL, or wirelesstechnologies such as infrared, radio, and microwave are included in thedefinition of medium. Disk and disc, as used herein, include CD, laserdisc, optical disc, digital versatile disc (DVD), floppy disk andBlu-ray disc where disks usually reproduce data magnetically, whilediscs reproduce data optically with lasers. Combinations of the aboveare also included within the scope of computer-readable media.

As used herein, including in the claims, “or” as used in a list of items(e.g., a list of items prefaced by a phrase such as “at least one of” or“one or more of”) indicates an inclusive list such that, for example, alist of at least one of A, B, or C means A or B or C or AB or AC or BCor ABC (i.e., A and B and C). Also, as used herein, the phrase “basedon” shall not be construed as a reference to a closed set of conditions.For example, an exemplary step that is described as “based on conditionA” may be based on both a condition A and a condition B withoutdeparting from the scope of the present disclosure. In other words, asused herein, the phrase “based on” shall be construed in the same manneras the phrase “based at least in part on.”

In the appended figures, similar components or features may have thesame reference label. Further, various components of the same type maybe distinguished by following the reference label by a dash and a secondlabel that distinguishes among the similar components. If just the firstreference label is used in the specification, the description isapplicable to any one of the similar components having the same firstreference label irrespective of the second reference label, or othersubsequent reference label.

The description set forth herein, in connection with the appendeddrawings, describes example configurations and does not represent allthe examples that may be implemented or that are within the scope of theclaims. The term “exemplary” used herein means “serving as an example,instance, or illustration,” and not “preferred” or “advantageous overother examples.” The detailed description includes specific details forthe purpose of providing an understanding of the described techniques.These techniques, however, may be practiced without these specificdetails. In some instances, well-known structures and devices are shownin block diagram form in order to avoid obscuring the concepts of thedescribed examples.

The description herein is provided to enable a person skilled in the artto make or use the disclosure. Various modifications to the disclosurewill be readily apparent to those skilled in the art, and the genericprinciples defined herein may be applied to other variations withoutdeparting from the scope of the disclosure. Thus, the disclosure is notlimited to the examples and designs described herein but is to beaccorded the broadest scope consistent with the principles and novelfeatures disclosed herein.

What is claimed is:
 1. A method for wireless communication at a userequipment (UE), comprising: receiving one or more messages indicatingthat a base station supports allocating resources for sidelinkcommunications using a first interface and a New Radio (NR) PC5interface; transmitting one or more sidelink information message to thebase station using the first interface that indicates that sidelinkcommunications are to be performed using either the NR PC5 interface orboth the first interface and the NR PC5 interface; receiving aconfiguration message from the base station that comprises an indicationof available sidelink resources; and transmitting, based at least inpart on the configuration message, a request for resources within theavailable sidelink resources, wherein the request for resources is basedat least in part on whether the request for resources is associated withthe NR PC5 interface or both the first interface and the NR PC5interface.
 2. The method of claim 1, further comprising: receivingdownlink control information (DCI) in a control channel; descramblingthe DCI to obtain a resource grant allocating resources within theavailable sidelink resources; and performing the sidelink communicationsusing the allocated resources.
 3. The method of claim 1, furthercomprising: receiving downlink control information (DCI) in a controlchannel; descrambling the DCI for determining whether the DCI includes aresource grant allocating resources to the first interface; anddescrambling the DCI for determining whether the DCI includes a resourcegrant allocating resources to the NR PC5 interface.
 4. The method ofclaim 1, further comprising: receiving downlink control information(DCI) in a control channel; descrambling the DCI for determining whetherthe DCI includes a resource grant allocating resources to the NR PC5interface associated with a first transmission type; and descramblingthe DCI for determining whether the DCI includes a resource grantallocating resources to the NR PC5 interface associated with a secondtransmission type.
 5. The method of claim 1, wherein the one or moresidelink information message indicates a transmission type, a trafficprofile, a quality of service indicator, a service type indicator, orany combination thereof, for the sidelink communications.
 6. The methodof claim 1, wherein the configuration message indicates a mappingassignment for a logical channel associated with the first interface orthe NR PC5 interface.
 7. The method of claim 1, wherein theconfiguration message is a radio resource control (RRC) message.
 8. Themethod of claim 1, wherein the one or more messages is a systeminformation block (SIB) message that is broadcast by the base station.9. The method of claim 1, wherein the first interface is associated witha Long Term Evolution (LTE) Radio Access Technology (RAT) and the NR PC5interface is associated with an NR RAT.
 10. The method of claim 1,wherein the first interface is a legacy interface.
 11. A method forwireless communication at a base station, comprising: receiving one ormore sidelink information message from a user equipment (UE) using afirst interface indicating that sidelink communications are to beperformed using a New Radio (NR) PC5 interface or both the firstinterface and the NR PC5 interface; transmitting a configuration messageto the UE that comprises an indication of available sidelink resources;and receiving, based at least in part on the configuration message, arequest for resources within the available sidelink resources, whereinthe request for resources is based at least in part on whether therequest for resources is associated with the NR PC5 interface or boththe first interface and the NR PC5 interface.
 12. The method of claim11, further comprising: generating a resource grant allocating resourceswithin the available sidelink resources to perform the sidelinkcommunications; scrambling the resource grant to generate a scrambledresource grant; and transmitting, in a control channel, downlink controlinformation (DCI) that comprises the scrambled resource grant.
 13. Themethod of claim 11, further comprising: generating a first resourcegrant allocating first resources within the available sidelink resourcesto the first interface and a second resource grant allocating secondresources within the available sidelink resources to the NR PC5interface; scrambling the first resource grant to generate a firstscrambled resource grant; scrambling the second resource grant togenerate a second scrambled resource grant; and transmitting, in acontrol channel, downlink control information (DCI) that comprises thefirst scrambled resource grant and the second scrambled resource grant.14. The method of claim 11, further comprising: generating a firstresource grant allocating first resources within the available sidelinkresources to the NR PC5 interface and a second resource grant allocatingsecond resources within the available sidelink resources to the NR PC5interface; scrambling the first resource grant to generate a firstscrambled resource grant; scrambling the second resource grant togenerate a second scrambled resource grant; and transmitting, in acontrol channel, downlink control information (DCI) that comprises thefirst scrambled resource grant and the second scrambled resource grant.15. The method of claim 11, wherein the one or more sidelink informationmessage identifies a transmission type, a traffic profile, a quality ofservice indicator, a service type indicator, or any combination thereof,for the sidelink communications.
 16. The method of claim 11, wherein theconfiguration message is a radio resource control (RRC) message.
 17. Themethod of claim 11, further comprising: transmitting a systeminformation block (SIB) message indicating support for allocatingresources for sidelink communications using the first interface and theNR PC5 interface.
 18. The method of claim 11, wherein the firstinterface is associated with a Long Term Evolution (LTE) Radio AccessTechnology (RAT) and the NR PC5 interface is associated with an NR RAT.19. The method of claim 11, wherein the first interface is a legacyinterface.
 20. An apparatus for wireless communications, comprising: atleast one processor, at least one memory in electronic communicationwith the at least one processor; and instructions stored in the at leastone memory and executable by the at least one processor individually orcollectively, to cause the apparatus to: receive one or more messagesindicating that a base station supports allocating resources forsidelink communications using a first interface and a New Radio (NR) PC5interface that is different from the first interface; transmit one ormore sidelink information messages to the base station using the firstinterface that indicates that sidelink communications are to beperformed using either the NR PC5 interface or both the first interfaceand the NR PC5 interface; receive a configuration message from the basestation that comprises an indication of available sidelink resources;and transmit, based at least in part on the configuration message, arequest for resources within the available sidelink resources, whereinthe request for resources is based at least in part on whether therequest for resources is associated with the NR PC5 interface or boththe first interface and the NR PC5 interface.
 21. The apparatus of claim20, wherein the instructions are further executable by the at least oneprocessor to cause the apparatus to: receive downlink controlinformation (DCI) in a control channel; descramble the DCI to obtain aresource grant allocating resources within the available sidelinkresources; and perform the sidelink communications using the allocatedresources.
 22. An apparatus for wireless communications, comprising: atleast one processor, at least one memory in electronic communicationwith the at least one processor; and instructions stored in the at leastone memory and executable by the at least one processor individually orcollectively, to cause the apparatus to: receive one or more sidelinkinformation messages from a user equipment (UE) using a first interfaceindicating that sidelink communications are to be performed using a NewRadio (NR) PC5 interface or both the first interface and the NR PC5interface; transmit a configuration message to the UE that comprises anindication of available sidelink resources; and receive, based at leastin part on the configuration message, a request for resources within theavailable sidelink resources, wherein the request for resources is basedat least in part on whether the request for resources is associated withthe NR PC5 interface or both the first interface and the NR PC5interface.